1. Sounds just like the one I use.
2. No if it is working you don't need to replace anything, but you might want to. I just did a capacitor replace and the power cleaner and flex amp and new 2 watt speaker mod on mine last weekend (all parts from Helder Game Tech) and it sounds so much better than it did.
3. Yes if you do it wrong. Depending on what you do wrong it might be fixable or it might be completely ruined. Watch videos of the mods you want to do first and just watch a lot of soldering videos period. Maybe get a soldering practice kit off of Amazon.

Another super useful tool I recommend getting (especially if you decide to do the capacitors) is some kind of magnification with a light. I got a magnifying lens with an integrated ring-light, but I really wish I had gotten a digital one now that I have used it a few times. Something with variable zoom and none of the distortion from the lens would have been nice.

Also a silicon soldering mat is nice to have and a good micro-electronic tool set like the Pro tech Toolkit from iFixIt is almost required. A good pair of tweezers (I like to have both a squeeze to hold and squeeze to release pair, both included in the iFixIt kit) and a good flush cutter are must have tools though. Decent solder as well. If your iron comes with some just toss it out because it is probably shitty. I like using a no-clean liquid flux, but I have run into a few places where a thicker flux would have been nice.

Here is what I use.

https://www.amazon.com/dp/B00425FUW2

https://www.amazon.com/dp/B075WTX9WY