1) Best to remove any battery that old. How often do you need a real time clock on an A2000?
2) That is an A2090. Non-bootable SCSI controller. 2091 or better is suited to you.
3) Hmmm
4) Yes
5) Your 2090 should do the trick.
6) Probably but you will need software to use the RW aspect.
7) AsimCDFS is best. $5-10 USD on eBay.

Get 3.1 ROMs and install OS 3.1

9) See #8
10) Huh?
11) Can't help ya there. I wouldn't do it or encourage it.
