Did some testing not too long ago and made some conclusions.

Group1

Rune Enhancement Effect:
It's pretty much important to max out. No much to say other than it will strengthen the runes even more. 5/5

Vallation Effect:
Not that it's bad, but it'll be pretty pointless if u go against a mob that does multiple types of elemental spells 0/5

Lunge Effect:
Im on a debate on whether or not to max this out, but testing it out. It seems to keep the max dmg to where it's at, but starting to believe if RUNs really need it? 5/5

Pflug Effect:
Do RUNs really use this ability, but then again do they need to enhance it when mobs do other types of status effects. 0/5

Gambit Effect:
Wanted to cap this, but it will be pointless again if mobs do other elemental spells. 0/5

Group 2

Battuta:
So far im loving it. Max counter dmg is 99 spike dmg. Was hoping it does more, but it seems fine plus it increase your parry much more. The downside is that it last 5 min. It should be around 3 min to balance it out if the duration last for 1min 30sec. That's crazy and it's a really good ability. 5/5

Rayke:
I feel this ability is useless atm. The duration is really short, but I think that's all gravy for manaburners. Just have to go old school and do a set time for RUN to use the effect and manas cast at the same time. 1/5

Inspiration:
Best ability ever. While valliation or valliance up and did a test and casted cure 4, pro 4, shell 4 the recast was around 2-3 secs. I definitely gonna make ppl use that more often. The sad part u gonna waste more MP than u think so use it wisely. Hopefully they'll release gear for RUN that at least give it auto-refresh +5 or something, but I doubt that will happen. 4/5....may end up being 5/5

Sleight of Sword:
Don't get it, it's pointless. Useless ability. 0/5

Overall there's only 2 abilities that are a must have on group 1 and the same on group 2. Never understood why SE creates useless abilities as merits...idk.