"Things I wish I'd known" mostly amount to things I still wish to know. Mainly, traditional nuances of worship and home life, which are missing in small convert parishes. But in the spirit that you mean, I can't think of anything I wish I'd known. I kept my expectations very minimal, and was mostly just looking for a spiritual authority of good proveniance to place myself under. As an ex- Dorothy Day -
style anarchist, I thought of it more as submitting to a spiritual patrimony -- taking my medicine -- than something that would bring me personal benefits. In the event, conversion did bring me great personal benefits, but those could come as pleasant surprises, more of which I receive all the time. If I allowed myself, I could be bothered by any number of things in American Orthodoxy, but I'm just old enough to have learnt that that kind of vexation is the fruit of one's own mind and not of the trespasses of others (trespassers tho they may be, as are we all; Lord, have mercy).