SMD LEDs would be much brighter, stick and peel, no resistors needed, and you'd probably need fewer of them and less power.
Buuuut you didn't come here asking for what ways this could've been better.
Use a new soldering iron tip. Get a decent one. Trying to solder that many things with a known oxidized-beyond-usefulness tip is more pointless than Sysiphus' job.
Then bend your leads so they don't fall out, it should frankly take you more time to stick things onto the board than it does to solder them. Hot iron, 1-2 seconds is all it takes per point. For big through hole things, using at least 1.0mm solder wire also helps speed along the process. Don't bother using ultra thin stuff.