1. If you cleared Rising Ruby you should be fine with rebalanced, the difficulty level will be fairly similar. However, I'd suggest that you play with the EXP share on, as the mod is balanced around it being on the entire time and you'll fall behind quickly without it.
2. I've seen one person successfully Nuzlocke insanity, so it's definitely possible, but I wouldn't recommend it.
3. You're expected to be low to mid 80's by the Elite 4.
4. I've edited the Looker quest battles, the post game rival battles and the entire Battle Chateau, including Gym Leader and Elite Four rematches. I can't say if they're actually good battles though, as I never bothered grinding to a high enough Chateau rank to test them.
I can definitely offer some advice for a Nuzlocke playthrough:
- Use the restaurants to grind; you'll earn more money than you spend and they all have teams that give a lot of EXP. Be aware that they have silly gimmick sets and might not be free EXP until you're a higher level than them.
- Some of the multi battles can be pretty nasty, so you may want to focus on defeating one opponent first to make them easier.
- Evolve your starter before challenging Viola, and consider picking up the Smack Down TM in the Santalune mart if you choose Froakie.
- Route trainers tend to be at slightly lower levels than bosses, so if you're feeling overlevelled on a route it's probably not an issue.
- The first encounter on Route 2 is always a Speed Boost Torchic; it's meant to emulate the event one that was available when XY launched. It replaces the scripted Pidgey that some people like to skip in XY Nuzlockes, so may want to ignore it if you'd prefer a random encounter.
