Thoroughly recommend aeros, not from an airlines point of view because I'v never been there, but from an instructor's POV aerobatic pilots <b>in general</b> seem to be able to fly in more demanding conditions than non-aero pilots with the same number of hours.
It's really about pushing yourself, do you want to do it gradually on your own, making your own mistakes, or do you want to do it in a controlled, supervised environment?
Neil Williams "Aerobatics" is one of those books that if you are really into it, you can learn something new each time you read it. I've read it three times, and proven this rule to myself.
As to the aeroplanes, I haven't flown enough types aerobatically to say if the C152 is the ideal trainer, but it does most things reasonably well and some things (stall turns, barrel rolls, aileron rolls) very well. If you really crank it up you can also get a four point roll out of it, although you end up pointing down a loooooooong way!
In general the more types of flying you do, the better pilot you will be. THink about how much better you felt after your night and IMC ratings. Same thing, but it always applies.
Safe flying
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Confident, cocky, lazy, dead.