1. 90 HP for a basic is pretty decent, weakness and resistance are standard, if a little unfortunate...psychic weakness can be quite a liability. Two retreat is a little pricey. Altogether average, but a little less advantageous than it might be for, say, 1 retreat.
2. The mechanic at play with the whole Poisoned business is interesting, and certainly pretty unique. The problem with it is, if you're going to Poison first turn and then attack next turn, you're going to take at least 20 between turns. If you can get him out first turn, it's possible you can get a kill second turn against a weak Defending Pokémon, but since there's no first turn damage, the possibility you'll donk is close to nil.
3. It's actually been awhile since I've played competitively, so I'm woefully underknowledged about the current cards, but if there's a current card that lets you move damage counters around, that would be the one to use. You'll have to be careful, though, to avoid Crobat drops. Potions, of course, or Moomoo milk, but I don't like the flippiness.
4. See above. I don't know what kind of deck this would work in, so it might be considered a tech itself. Anything that lets you (re)move damage counters.
5. I love Seviper, but the more computer-y artworks always kinda disappoint me. I like the glint on his tail, and his eyes are delightfully evil, and the lighting is cool. 3.75/5
6. Overall, interesting card with some good start-game potential, but it soon loses potential as the hits from opposing Pokémon become more and more powerful mid-to-late-game. 3/5 at best, unfortunately lacklustre.