97 monte carlo transmission concerns?

So a while back I swapped trans fluid in my monte. First time I ever did it, so I was paranoid that I would overtighten the pan bolts when I was done, and it would leak. I took my time doing it, and went gentle with it. No leaks whatsoever, so I was all set.

So this morning my gf starts my car to let it warm up, and I take her to school. It was sluggish and slipping. I drove her like a mile to college and came back. For some stupid reason I thought the brake caliper was sticking because I smelled a strange odor after dropping her off. So when I got home I put it in reverse and gave it some gas (in hopes to pry the brakes loose), and it made a strange noise. I eventually found the dreaded red puddle on the passenger side of my driveway (which my gf didn't mention) so I immediately turned it off. I checked the fluid (cold to prevent further damage) and it was about halfway between the bottom, and the add fluid line. It was still the same color as new fluid.

I poured some trans fluid in, and looked underneath. Noticed it was the back of the pan. Pretty sure the cold weather made the gasket contract, and form a leak. Tonight I will take a torque wrench to all of the bolts and tighten to factory specs. Then ill fill with high mileage fluid and lucas oil transmission fix.

I'm. Just wondering if after filling it with new fluid and fixing the leak if there will be some guarenteed major problems, or if it should be fine. Obviously anything could happen, so I just want to know what usually happens. By the way its a 97 chevrolet monte carlo LS with a 3.1 L V6, and I believe a 4T60-E 4 speed automatic tranny. Thank you in advanced.