I'm planning to re-use the 3.4 oil baffle for my swap. I've cut one of the necessary holes into it for the oil pickup, but was wanting to know if it's okay to completely cut off the corner where the other leg for the oil pickup bolts through. I want to cut along the yellow line. Is that bad? What has everyone else done for this part?

that is the wrong one to cut off anyways. But you don't need to cut it off. Just cur the lip off. And you will want to cut the left side one down.

I've double-checked about a dozen times and I believe I marked the correct one to cut off. But regardless, if only the lip is cut off, then how does the top part of the pickup form a tight seal against the engine?

Hamish is right. You grind the lip off of it and it will work. I even have the bolt there. Just tighten the two bolts for the pickup before you tighten the mounting bolts for the pickup.

It's also the bottom left tab. Not the top one.

OMFG, am I totally missing something or are you guys on something?
Here's what it will look like when I install it. The same corner that I marked in the first picture is the same one that needs to be modified here.