The 102mm measurement is the length of the axle so you will lose 5mm off the axle length when fitted. This could cause problems with your chainline and may cause contact with your frame or derailleurs in use. You should try to match the bottom bracket you have as closely as possible.

You should contact your frame manufacturer to ask what the ideal chain line is or check the manufacturer of the chainset you are fitting to get a the correct bottom bracket length for that chainline. Because it relies on both the frame and chainset it is very hard to tell.

Campagnolo usually used ISO taper and Shimano used JIS taper. I wouldn't recommend using this for a Shimano chaisnet of any age, you should probably use a Shimano Square taper bottom bracket to be sure of fitment

Yes you can use this bottom bracket with the Record crank arms.

I can confirm these parts will indeed be compatible.

An Athena crankset should fit the Chrous BB fine.