well, that is good idea, disable post counts in welcoming section and off topic, add reputation system,that will in rease meaningful posts and decrease the spam posts. People mostly going for off topic section to increase the posts counts, well , I dont see the problem of welcoming every player, theres no harm of it at all, but getting to know people is good though.
For spam, just follow the rules xtasia create. the report if you found a real spam.
Is not going to grow your penis because you have over9000 post Maybe you need that life.
I think that the "Welcome new citizens" section is worst than Off-Topic. In Off-Topic at least there is serious posts D:
In my opinión, probably the best solution is to detele Welcome forum and make a pinned thread in Off-Topic for people introduce oneself.
I agree with the pinned topic, this will prevent every new topic per new user. nice suggestion.