I'm going to answer you with how I see all of these questions:
1. I'd say it depends on you, imo a defensive and campy villager would fare better than aggressive because when looking at the frames your go to fast move is going to be rising nair and jab. This is also without a "good" grab to take advantage shield happy opponents, can't tell you how often I've gotten too offense happy because I had some momentum and lost it because I had tried to mix in a grab that they could react to and suddenly I'm on the back foot. Playing campy will come down to making your moves as safe as possible, well spaced fairs/bairs as well as rockets are the mainstay of villager neutral. Retreating sh nairs are also an excellent get out option for resetting neutral. If you're more of a visual learner then I'd advise watching some of Ranai's or Zee's videos to study some of the techniques they employ.
2. All of your zoning tools are pretty good for gimping, depending on the character and how they're recovering you can space fair/bair to tap them and cut their momentum when recovering or even gimp/kill them outright. Because of the distance balloon trip covers you're able to take your options out farther than most so dropping them down with nairs and dairs is also viable considering the lost lasting nature on both of those moves.
3. Someone made a post like this not too long ago, you can search it if you want my full explanation but TL;DR I feel pikachu provides excellent coverage for a majority of his bad m/u's.
4. Pretty much covered this in 1 and 2 but to drive it home, it's use is really versatile. It's fast, it can set up combos, it can frame trap [ after performing a rising sh nair you can still throw out a second one right before you hit the ground, it's unsafe since you have to be so close to your opponent and the ground to perform this but it's an option if you find yourself in this position. It'll start and the hitbox will come out, then you'll land immediately. ]
5. Villager has a plethora of kill options, pretty sure this is also already a thread somewhere but from my experience he doesn't have many "I touched you at neutral, my follow up is going to kill you for sure." like say old diddy had off of his grab. It'll come down to conditioning and punishing unsafe options. Bowling ball is a pretty great kill move despite it's utter lack of range, when it comes to edgeguarding it's use really boils down to who you're fighting against and how they're recovering. If you want to overgeneralize then a simple flowchart for killing with it off edge is
A. Are they recovering high? if yes knock them back down using fair/bair/dair/nair...whichever is appropriate. If no then proceed to B.
B. Time teh ballz to cover their recovery.
It really shouldn't just boil down to this but it's a skeleton for generic application and multiple factors should be taken into account mid match before you decide this is how you should guard. It can also be used to if you space it perfectly to punish aggression from opponents, like using a retreating kara fsmash to space away from an approaching move and punish with the ball, or retreating perfect pivoted fsmash for the same result. Gimps will obviously work too, and while all stage spikes are stocks that could've been saved with execution you have the ability to constantly test your opponent's tech skill with run off bair should they be sliding up the side of the stage for recovery. Aside from gimping you can outright spike with triple turnips. Upair will net you a good amount of stocks if you can punish bad jumps or get them as a follow up from a juggle. Bair/Fair can also kill if shot at a close range from villager as well, you'll get a feel for the distance and you'll notice a significant difference in knock back even at lower percents. At kill percents you can follow up a Downsmash with Upsmash for kill [ try to avoid using bowling ball here as the knock back will be cut in half due to buried mechanics; Upsmash avoids this by first lifting the opponent, then launching. ] Lastly that comes to mind is uptilt and dtilt, believe it or not I've netted a few kills off of dtilt. It's strongest nearest villager and you really wont kill anyone with the outer part of this move, but it can be used if you find you're having difficulty landing other moves and find the opportunity at higher percents...and I mean higher percents. Uptilt on the other hand can kill at reasonable percents and is overall a really solid move, it's an anti-air that can lift opponents off the ground and covers spotdodges/ rolls that attempt to cross you up but don't go far enough. Even if you don't kill with it the knock back is good for setting up juggle scenarios that can setup for kill options or more dmg. My Advice is don't focus too heavily on kills, do your best to control neutral as hard as you can and find ways to simply incorporate these options in when they're appropriate.
Anyway that's how I'd answer your 5 questions, it's alot so I really hope this'll help you out, good luck neighboring people and if you have any more questions just ask.
