Re: How long did it take to get your forum where you wanted it?
It probably took me about 3 months to get it 90% the way I wanted. After 7 months I've just added vBSEO so it's starting all over again. But it ranks well and the pages are almost fully indexed now and it's exactly 4 weeks since we installed it.
But as you say, you're never fully finished, it's a continuing circle. If it were to stay where it is, it would be finished. But I have some advertising channels to get sorted and I hope to bring in thousands of unique extra visits each day if it comes off. Then I'll need to move servers to cope. So I might just move now while I can handle it without the pressure.
I think if your site is finished, it will be finished, literally. You need to keep changing your site all the time to keep up with demand and to keep your members happy.