Warm engine miss and oil leak in Mayas Previa

I posted last week and I've learned a bit here. Trying to search this forum to find answers is a bit tricky for me unfortunately, I hope I'm not seeming too lazy. Best I can tell this neat van has 2 problems. One is a oil leak that comes down onto the header pipe a bit in front of the catalytic converter. It continues to leak for quite a while after it's shut down so I'm pretty sure this is the common valve cover leak I've read about. Can anyone point me in a direction to find out what is involved to fix this? It is annoying, it leaves spots and smells bad.

Other problem... The engine starts up great, and seems to run perfectly 'til it comes up to temperature. Once warmed up it runs fine if I drive real gentle (which I am inclined to do anyhow)... but if I give it much throttle it misses under acceleration sometimes. I wonder if there is some sort of common problem I should be looking for.

The car is a 95 Previa LE/SC All Track, I'm an OK mechanic but don't know much about these. I gambled on it last week for my16 year old daughter... we gave $500 for it.

fix the valve cover problems... it will likely fix those issues you described
you may also want to replace the distributor o'ring while you're at it because it's in that same area