Yes, the TA lockring tool. If you don't want to buy it, use a lockring from a cup-and-cone BB instead; the TA lockring is very soft alloy and will be ruined if you don't have the correct tool.

Yes. You need the 6 notch TA lockring spanner. Nothing else will do. Don't use a Shimano tool or a standard lockring hooked spanner. The lockring is made of fairly soft metal and if you use something else you will probably strip one or more of the notches.
You also need a standard Shimano bottom-bracket tool for the cups. You only need one of those if you are fitting English threaded cups.

A difference of 1 or even 2mm in chainline will typically have an affect only if it the BB is too short and causes the crank to hit the frameset. If the BB is too long, modern chains are very flexy side to side and can take up the slack.

Note, if you spend all your time in the big-front chainwheel and big-rear sprocket, this will be the worst case scenario for a long bottom bracket and a standard rear cassette. This is a really bad scenario anyway and you typically are better off learning to use the small front ring and a middling rear sprocket as there will be much much less twisting and wearing of the chain.

This bottom bracket in particular can be micro adjusted because there are lockrings on both sides, so you can get the perfect chainline - just buy something a tiny bit BIGGER than what you actually need.