#1 is as much up to you guys as us
#2 is something I'd like to see a bit more of, and with the skins being so easily made optional even within purecheck, it's a shame that we don't have more. I'm only aware of ~3-5 pk3s with alternate skins for anything. If you guys start making more of them and they look good + aren't using super-bright colors designed to give you an advantage, I know that we, for one, would allow and enjoy them on Puretrem and I expect that other servers would as well.
#3 not only requires the infrastructure to submit all the data, but because servers run very different settings (to say nothing of modifications that go far beyond changing included cvars), stats across servers are basically incomparable and this can't work.
#7-8 are already done by tons of players outside of the included server browser. Use qtracker, kquery, qstat, or a variety of other external programs that can handle this more conveniently than an internal browser ever can/will/should
#9 is actually rather difficult for security reasons as has been discussed in multiple topics. So far nobody has presented a foolproof proposition, much less implemented one.
#12 is Khalsa. Specifying "not dev team members" is an oxymoron, because when someone is put in charge of these things, he/she becomes a member of the dev team.