I was super confused when I joined here, not by the postbits and the graphics, but by the way everyone changed their username every few weeks. Thankfully, that seems to have calmed down now - only a few people still do the themed username thing - so I think we're already a more noob-friendly place then we used to be.
If we move to vB5 and make some design changes, my biggest priorities would be increasing the default font size in a few places (having moved to a 1080p monitor I've resorted to browsing TLS with a 125% zoom because it's so small, but that makes the images blurry, so it's not ideal) and fixing a few colour inconsistencies (e.g. the link colour that is used in posts doesn't show up in previews).
As for the postbits, how about this as a compromise: let users choose which user groups show up below their name. In my case, I'm happy for people to see that I'm the Community Manager but I don't particularly feel the need to show them that I'm a donator or an elite member, and I'd hide them if I could.
I'd also suggest that some people shrink their AKA fields to only the names people actually use when referring to them (e.g. when was the last time someone on TLS said "Hey, Ariadne" when addressing Tres?), but that's up to each individual and shouldn't really be a forum policy.
It's important to balance the desires of our existing members with the potential concerns of our new ones.