Does it take away posting time limit and restrictions like that or is it just a status thing?
Donating is not a way to buy a right to spam from start and/or avoid "the fuss" of being a useful, constructive, helpful addition to our community; even, if you have tons of
BTC to dump off. I can understand the reason you ask such a question since is a tipical n00b one in every forum across the Internet; however, to take away (gradually) time limit and restrictions you shall increase in
rank by contributing to community.
Donating is a way to show appreciation for the existence of the Bitcointalk forum by contributing to its expenses. Donators, receive, as an appreciation token to their gesture: a special title (
a sub-rank), a colored "who's online" color, access to an exclusive forum section (both Donators and VIPs) and the ability to create a custom title for yourself (VIP status only).