Is it just me or does it seem custom races are broken?

Also can we load up the current races and then modify them?

Not sure what you mean by "broken"? Get Les value than a prebuilt race? Yes.

I think this is intentional as the prebuilts all have abilities I wouldn't often bother putting on a custom race.

I also think the custom races stuff is... not optimal.

For example, if I don't like the ships of, say, the Klackons (and I don't), I can't create a race with better looking ships (like the Darlok or Meklar) with the traits of the Klackons since I'm 30 points short.

Complete list at the time of writing, patch 43.4 (hopefully without mistakes):

+20 points: Sakkra, Silicoid
+10 points: Alkari, Mrrshan
OK: Darlok, Psilon
-25 points: Terran
-30 points: Klackon
-40 points: Bulrathi
-50 points: Human, Meklar

And don't tell me that it can't be done. If it could be done in MoO2, it can be done here. At the very least they could implement some sort of race packages, where you can recreate any premade race and get a points bonus so you can start playing (but if you remove one of the racial picks, you'd lose the bonus points).