I'm honestly not too sure about their weapons on the suits, i think they only ever shot once and even then it missed so i never paid much attention to the name of the weapons, also was more thinking along the lines of "holy shit 3/4 of army is already gone" XD.
I believe the commander was attached to a squad of 4 and the other might of been 2-3, can't really remember too well. If next time he's using that stuff again i'll be sure to check his rules and points myself (and other players too) cause i just didn't understand my enemy well enough though if it was an illegal list that kinda sucks ass, pretty sure he came in third for the whole thing
As for the Grey Knights i agree it would be tough, if i was aware that he couldn't in fact assault me right after teleporting and i managed to get that one more 6 to deny it, i'm not sure how it would of ended in the end, i could of just kept slamming shots into him from range whil he tried to close the distance, though i'm assuming he still would of got in front because of the teleporter. i did also manage to take a dread knight off the table straight up by just slamming everything i had and bad saving rolls by him and his terminators were still troops and i had a furor and malleus kill teams so asides from the two HQ i had the two kill teams that countered everything else. If he didn't charge me after teleporting in front of me i think i could of killed 2 terminators maybe the third with the furor nearby and slam the rest with the squad in front. It always sounds must more hopeful in post when you have time to think about what could of been, could of been done.
Also the Grand Master had two melee weapons. I know he counted it as two because he used the sword(Think it might of been either a relic or a power sword cause i had to do invul rolls so it was something that was ap2) in his melee so he could attack me first (with the hammer being unwieldy and all).
Be warned he who looks not where he walks for he may find himself facing death itself.