Reckon on at least a couple of hundred miles to get properly confident if you've not ridden a recumbent before, but you should get the hang of starting and stopping relatively quickly with practice. I can't imagine the prospect of doing a Basil into the canal helps with the stress levels.
The attention is, unfortunately, an occupational hazard. At least half of it is good-natured, if frequently unoriginal. All things being equal, I'd rather that people a) stare at me than drive into me and b) shout 'witty' remarks about the bike rather than sexist or homophobic comments.