OK, let's try to analyse this for balance. (Sorry I was missing for a bit; I had technical problems recently and was struggling just to do votecounts in my own game. When your connection to the site is so unreliable that you spend 20 minutes trying to do a vote count, you kind-of forget trying to do anything else.)
Here's what the setup looks like, summarized (I basically just do this to make things easier for myself, so that I don't have to keep rereading your OP in order to keep track of the current version of the setup:
Town: (variant) Neighborizer, 1-shot Gunsmith, Weak Doctor, Universal Backup, Tracker, 5 VT
Scum: Rolecop, Backup Rolecop, Goon (relevant rules: daytalk, can action+kill)
The first thing to note is that some roles are much more powerful than others. When balancing a setup, first you try to get it approximately town/scum balanced and then you work on the finer details. If we're only looking at approximate balance, we can assume that the less powerful roles are dwarfed by the more powerful ones, and thus balancing the setup on the more powerful ones alone will get things approximately right.
In this case, some of the town's roles are fairly weak ones. A Neighbourizer is not all that strong of a role for its night action (although it's fun to play with!), and I'm not sure you can conclude much from the fact that the player has the role either (statistically, neighbourizers are usually town, but then players as a whole are also usually town, so I'm not sure if the mere fact of being a neighbourizer makes a player more or less likely scum). Universal Backup is best seen as a protective role (it doesn't protect the player, but it does protect their power); it's equivalent to preventing the first death of a power role. Tracker is typically only really useful if it scans the scum making the kill, in which case that's normally enough to frame the scum, but scanning anyone else rarely gives much useful evidence. A neat mathematical fact is that (if scum kill randomly, which is not the case especially with Rolecops around) the increasing chance over time that the Tracker has to find the killer is exactly counterbalanced by the decreasing chance over time that the Tracker has of still being alive, which would normally mean that the Tracker had a 1/13 chance of hitting per night phase in the game, or around 4½/13 (N5 investigative results are only about half as powerful due to the chance that either the game is over, or that it's lylo and the investigator has to win a 1v1 against the scum they're accusing). In this case, the Universal Backup saves the first power role from being lost to a death, which will be on N2 on average (half the town is power roles), so we can up the Tracker's usefulness to 1/13+1/11+1/9+1/9+½/9 = about a 44% chance of catching scum, if aiming randomly. I'll call that around half a confirmation, because it's going to be aimed better than randomly.
In terms of the more powerful roles, we have a Weak Doctor and a 1-shot Gunsmith. The Gunsmith shot is almost certainly going to confirm its target, if not immediately, later in the game. If the Gunsmith scans town they'll get a useful "no gun" confirmation. If they scan scum, they'll get a truthful "gun" confirmation, but most of the scumteam can claim out of it. However, once a massclaim happens (probably in lylo), someone's going to point out that a rolecop in this setup is almost certainly scum (and it's a scum-leaning role in the first place), so the target's probably going to be caught out and lynched. (Scum could maybe fakeclaim, but in practice, most don't, and they don't have enough information to know what claims would work, so it's not worth trying to take that into account.) So with the Tracker and Gunsmith, we have a total of 1½ confirmations. The Weak Doctor is the best role here, getting a confirmation every night it survives and scans town. (Oddly, it doesn't want to scan scum. This confirms one scum to the town if properly breadcrumbed, but costs them a mislynch in most situations; getting 1 scum at the cost of 2 lynches is close to the typical town lynching performance anyway, so the power role hardly helped in that scenario. The exception is if town block a kill using the protective part of the same role; then scanning scum gets a confirmation too.) I think it's reasonable to expect that the Weak Doctor could confirm three townies entirely by itself (less is possible, but more is definitely also possible), especially with the Universal Backup around to potentially inherit the role if it would die early. It's also self-confirming because it's very hard to fakeclaim.
Do the Mafia power roles rein in town power at all? Well, they make it more likely that scum will shoot a power role on night 2 and later. That makes the Tracker a little less powerful, and increases the chance that the Weak Doctor can be stopped early, but not by that much. Actually, the main benefit Mafia get from this is that if they manage to shoot an investigative, then even if the investigative is "saved" by the Universal Backup, town at least can't draw any useful investigative results on the night that the investigative actually died; and the rolecops increase the chance of that happening. However, it's not that powerful for scum (especially with the natural delay that comes from using a rolecop, in which you can't usefully act on the results until the night after); it's maybe worth minus half a confirmation by letting the scum remove power roles more efficiently.
In total, I make this about 4 confirmations' worth of town power. The normal balance point for a Mini is about 3, so I suspect that this is townsided. Most of the problem here is not the high number of town power roles (5 isn't all that rare in a MIni), but rather the fact that town have a Weak Doctor (a very powerful role in its own right), plus the possibility of a backup to save it (especially if it dies early). There's also some amount of swing, in that the setup's balance depends heavily on the skill of the player who gets the Weak Doctor power; if the role is played badly town don't have much of a chance.
My suggestions to balance the setup are to either nerf the Weak Doctor (either via a modifier that makes it less powerful, such as limiting the shots, or via replacing it with a different town power role that's less powerful), or to replace the Universal Backup with a VT (which weakens the Weak Doctor considerably and the Tracker slightly) or with a role-specific backup of one of the weaker roles (or of a role that isn't in the setup). Note that if you replace the Universal Backup with a Backup Neighbourizer specifically , you're going to need to change the variant Neighbourizer to a Normal one to avoid having two greylist roles in the setup.
By the way, I have a couple of rules questions that are confusing me. One is what happens if the Universal Backup sees a 1-shot role die. Does the role get inherited even if the shot was used? If so, does the shot get recharged or not? The other is about what happens if two town power roles die on the same night (the Weak Doctor can end up dying at the same time that scum shoot another power role). The first question isn't answered by NAR, as it isn't a resolution order question. The second is a resolution order question, but one that's outside the normal sorts of situations that NAR deals with; I
believe
the answer is that the scum kill resolves after the Weak Doctor by tiebreak and thus the Weak Doctor role is inherited, but I'm not sure. As both of these relate to Universal Backup corner cases, it may well be that replacing the Universal Backup is the simplest course of action here.
