what to do with second Galahad and misc ??

I really like the right-hand smack Galahad (#2 in your list). Works very well vs. the tons of bots with physical shields. I wasn't sure at the outset but with practice I've gotten much better with rockets, and seen good results in battle.

What about a midrange Galahad? Tulumbas and Pins. That could be interresting, I think.

Plasma.

The Ork/ Pinata Galahad is decent in the right hands, but it excels on tight maps. The DB Griffin are already biased towards tight maps, while the Carnage is not the strongest mid-ranger. Thus I'd work on setups that work best on more open maps, and the Plasma is slightly stronger there. I'd say plasma is the strongest Galahad configuration, so in this case there are two things going for it.

Tulu Pins is a very poor config for the Galahad. It's weak on damage, weak on hitpoints and it can't dodge opposing mid-range rockets. Thus it will lose a dual to almost any opposing mid-range bot. A Doc, for example, is faster, has 20% more hitpoints, does 2x the burst damage and over 50% more DPS.

Yeah, Plasmahad. Plasma has about 2.5 times the DPS than Pinatas/Orkans, and the Galahad has not the capability to "death button" a heavy robot because it will only have one Orkan. DB setups work mainly because you will be able to take out the robot with a full load in very short time, at least if it is not at 100% health. Once you have to reload, Plasma is much, much better.

I've been running ork/pins on my second Galahad. Both of mine were plasma for a long time, but I wanted to try something new. I'll stick with the missles for now because of all the shield bots I'm currently seeing. I don't think you can go wrong with either choice.