1- for exotics you can get blueprints to upgrade em to max gear score. On March 3rd you won't be able to bring em to level 40 but shortly after you will.
2- Field proficiency caches (level ups after 30) start rewarding them, so you'll have a lot soon.
3- yup, one exotic weapon, one exotic gear piece.
4- correct, no point in hunting specifics now. Once the expansion drops there'll be bars under each attribute showing how close to a god roll it is. You can save god rolled attributes for recalibration. Basically, March 3rd will make it so that gear can drop with all god rolls and make it so that you have a library of godrolls to find and then have the chance to roll onto other gear. On March 3rd talents, some attributes and max gear score/level change, so the only thing worth farming until then is:
- exotics
- blueprints
- credits
- resources