Leave the standard bee sting roof aerial. Thieves see shark fin aerials as instant RNS510 targets.
If you could ask your mate what VCDS tweaks need doing, that would be great! I don't desperately need N, S, W, E showing on the Highline display, but it would be nice for completeness!
Having had a few RNS510s now, my advice is: get the newest one you can afford, but don't get hung up on SSD, it makes no difference to performance. Just fewer moving parts, so more reliable. The older ones suffered HDD failures. The performance gains (compared to A thru C models) came from faster processors and software. A non-SSD Q version is just as good as a S/T, but will be a bit cheaper.