Fixing low rpm dropoff rate...
 

There's probably a proper term for it...but I didn't know what else to call it. Basically, I'm annoyed at the fact that it takes so long for the RPMs to fall to the correct spot when shifting. Example: From a dead stop, put it in first, take off and rev to 2500. Clutch in, shift. I can't let the clutch back out until it falls down to 1800 RPM or so. It takes a long time to do that, probably three seconds. And people behind me get annoyed because my acceleration from a dead stop is so slow. Could it just be my shifting? I don't know. I've only been driving a stick for a month. All I know is that if I let the clutch out sooner, it forces it to drop down anyway, so there's no point in me doing that. Regardless, what would reduce the time between shifts? Lighter flywheel? Better clutch?

let someone who is used to driving a manual ride or drive it and see what they have to say

it may have something to do with timing being advanced. or may have something to do with air fuel or idle.

How could I tell if timing was advanced? It doesn't seem to have any idling problems or anything like that. It definitely could be an air to fuel problem, because my check engine light just came on yesterday. I haven't had the time to get it scanned, but my guess is it's an O2 sensor or A/F sensor.

Agreed.

It could be your shifting, or there's something wrong with your car. Getting someone who knows how to drive a manual drive your car can probably diagnose it better than we can. It's a little harded to actually say what's going on if when we don't see it in person or video.