Lol exping by grinding is worst shit ever. Leveling should be fun and you should like it, now it's a pain in ass to kill 932849242 scorpions, mantis and centaurs.
There should be questline from 1 to 5 in a single town, 5 to 10 to another etc. and somes like 15-20 hard questline with brotherhood/enclave/unity/raiders/ncr factions.
And yes, 5k exp for whole cave + quest it's fair. It takes some time, skilll, ammo, you can't just rush it with 10 mm pistol, queen radscorpions isn't soloable, so you need at least 2-3 levels or a friend, so you won't receive two levels at once.
I started a project, i have tools and concept. Now I'm stuck. If someone could help me with few questions about adding new objects and know a little about mapper pm me.