Re: Tools. What is absolutely necessary?
Bicycle tool kit.
I have one from spin doctor with an assortment of metric hex bits, sockets and small ratchet. This set alone built most of my bike.
Impact driver and rubber mallet
Case screws are stubborn and this prevents you from destroying them and having drill them out.
At least two, maybe more, because they break.
Keep the stand up at home and the hand pump on the bike
Quality cable cutters
Bicycle specific cutters are the best, I use Pedro brand cutters.
Dremel and cutting wheels, grinding and sanding bits
Metric wrench set
Metric hex set small
Metric hex set long handle T
Screw drivers, both Phillips and Standard
Needle nose pliers
Adjustable wrench, various sizes
Chain whip and cassette tool
Yellow fuel resistant teflon tape
Rtv silicone, oil resistant