What tech traps? I tried 3A, 236A, and 66A after 236B$ and they all whiffed. I'm not sure about 2A+B grounded though, I always just used 236K for my grounded enders.
For A+B I don't think anything is guaranteed after hitting, they can tech away pretty fast if I remember correctly
As far as a basic gameplan, he can dominate up close, but you have to keep in mind his annoying lack of range on 6B, BB, and even 236B.
2A and backstep are very hard to deal with.
It seems like if you try and play it safe and not throw out 236B stop them, Pat doesn't have offensive answer for 2A. After hitting with anything but 3A or if they block 1B, It's a good time to press the advantage, but BB in this situation will likely whiff on the second hit, the second hit of 6BBB string will whiff, and everything else is too slow. 3KK does not stun on CH and does very little damage. It's also a mid-high string which probably has to be carefully hit-confirmed or else is unsafe, and I'm not even sure whether it stands them up on hit. My solution was to just single-B. On block or hit, the second hit threatens, so I used that opportunity to get closer or 1K.
It's really annoying that Pat has great close range tools but is at the mercy of 2A. You have to space very carefully against someone who 2As a lot. It's best to discourage them as much as possible by backstep whiff punishing and 9B. If they start using other interrupts you can usually hurt them really bad with 6BBB. If they turtle up there should be no end to the 1B, single B, and low spam. If they duck it's time to pull out 66B/2A+B mixups.
This all doesn't take into account stepping and backstepping. 3A should be used a lot as part of your mid/low mixup to cover this especially if they like to try to high-poke you out of disadvantage since the TC is reliable. The problem is, if they block you're right in their face at severe disadvantage. If don't want to be giving them free mixups all the time, you have to do a lot of chasing down which feels really awkward because Pat's single-tap forward steps are the shortest I've ever seen so you have to dash in.
Even if they never stop 2Aing or backstep G, it's big problem which limits your game at advantage. This is why it's probably best to knock them down as much as possible instead of messing with them at advantage.
Most likely, the most important things to keep in mind will be whether then can 2A, punish 236B hard, or whether they can keep you out. They probably can't do all three... hmm Pyrrha probably can. If they can only 2A, then 236B them to stop them. If they can't 2A, rush that shit down. If they can do both 2A and punish, it might be good to keep them out? It's not that far-fetched when you consider how good 3A is. For example it worked pretty well against Maxi for example to just 3A, back off if it hits and whiff punish if they try to 2A you. If they stop 2Aing you can do the "normal" gameplan.
Idk, this is how I felt playing the character. It's really really awkward fighting people who know how to backstep safely or 2A a lot.