It's actually not so much of a massive jump like between 6 and 7, relatively speaking. That's when the last of the AI tactics boosts kick in from memory. The current AI8 I'm playing is only about 150% to 200% of AI7.
If you're having problems getting established in your home world on AI7, or just having problems getting anywhere, crank up the handicap on the start game page for yourself to +70% (this particular number is just to stop late-game research happening too quickly, rounding and all
), and try starting a game like that. If you can get a foothold, then expand at that level, you can try shifting it down by 20% next game, and so on.
Another thing, is essentially a cheap and nasty trick to getting started with as minimal finesse as possible.
Essentially don't worry about any wormhole defenses at the beginning, nor about putting any harvesters on your resource points. Just build another few space docks until you've got at least one per wormhole, or minimum of four, then set each one to be on free attack, dumping your troops between each wormhole and your base. Rather close to the wormhole, but not too close. Set each one on repeat, and have it build one of each of your troops. Toss a couple of MLRS near your space docks/command station, then un-pause the game and wait.
Basically most of the enemies will fly straight towards your docks/command center. They'll fly through however many guys you've got, usually not many at the start, all your other ships not near the wormhole the enemies are flying out will converge on them, and essentially the guys will be nibbled to pieces; the MLRS turrets are backup in case things like bombers (with a little more shielding) manage to make it through.
Once you've got enough forces near each wormhole, move them closer, keep them on free-attack, and build a tractor turret or two near each wormhole. Once you've got that in place, pause your space docks, use the resources building up to finally build your harvesters/etc, then start the game from there.
Takes about 20-30 minutes to pull this off normally and really flattens your resource gains at the start of the game, so it might cause problems later on. On the other hand it's still the only reliable method I have for starting on a 5+ wormhole world when I've got a Special Forces Commander AI or two running around.