Dawn of War Codex

Weirdboy has the strangest upgrades.

https://dawnofwar.info/codex.php?page=elite/weirdboy#upgrades

I'm not sure how to tell which are good or bad, for the most part the bonus health on them is just nice to have since your Weirdboy should be avoiding direct damage and can run and heal while abilities are on cooldown. "Over Dere!" has been hard for me to aim and seems like it isn't that strong even when it works so I usually pick Warpath when I want to make my green guys a bit more blurry, but it doesn't seem that useful to me in general.

Bigga Brains giving 500 extra energy is nice, but I rarely actually use Foot of Gork as I'm too busy casting Warp Vomit and Zzap to save up the 750 for stompin.

Am I missing out on Weirdboy skills by avoiding upgrading in most games?

Warpath is a MUST BUY
It makes your squads less squishy vs range, and your sluggas will just roll over anything at crazy speed with it. It's really insanely good with orks, and especially with sluggas, or also nobz.
Remember that warpath also applies on the weirdboy, so it's great to save him from bad fights, without retreating.
Warpath also works on retreating units, you can save some really low hp units with it.

Bigga brain for Over dere is tricky to use.
It's really not an ability for newbies, you'll have to know perfectly how it works, and train a lot, to be able to use it perfectly.
So as long as you are not confortable with it, don't buy it.
But when you know how it works, it can be really good, but not as good as warpath.
And you can have some nice combos with it : over dere + KN kaboom, over dere + MB mega rumbla, over dere + WB big stomp. But again, you'll have to be really confortable with it, know the ability timings, the over dere range, etc. It's better to train alone first.
Over dere also works on retreating units, you can save units from nades or things like that.

Warphead, for Foot of Gork, is really a luxury upgrade imo. I'll buy it only if I'm T3, with max pop.
Because Foot of gork costs a ton of energy, and you can just retreat out of it to receive close to no damage. You'll have to use Foot of gork with an other source of knockack to guarantee a hit with the foot.