Ok...looking at your list.....
T. kirtlandi (Twig snake) Never kept it. Word is that they are hardy and not ill natured. They are Lethal.
Oxebellus fulgidus (Green vine Snake) Kept a few. Generaly bad tempered snakes that eat mice readily. Require at the very least a 55gl tank for a home. large specimens can envenomate, but to my experience, it is rather mild. Still take care in handling.
Ahaetula sp. (Long nosed Vine) A small (under 4') active group that has the unique quality of having Binocular vision due to the forward placement of the eyes. A lizard eater, the venom is very mild. This is probably your best pick for a starter. Scan thru these posts for care recomendations.
Plus:
B. dendraphila (the Mangrove Snake) a larger (to about 7')species. can be tricky to get started (need to be kept moist when young) Venom not an issue in babies, though larger specimens should be handled carefully. can sometimes be nippy.
Boiga sp. (Cat Snakes) All members of this genus are reasonably safe if you apply sensible handling techiques. None are lethal but some are potent enough to cause concern. Learn about the individual before you buy.
Chrysopelea (Flying Snakes) Three species. Mainly lizard and frog eaters (though the two larger species will take mice). Hardy. Venom mild. Best kept moist and not handled.
Langha nastra (Madagascar Twig) Inoffensive, mild venom should not be an issue. Eats lizards.
Hope this will help.
Frank
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"The luxury of not getting involved departed with the last lifeboat Skipper..."