It seems the biggest problem is your 150 socials draining the guildbank with those 100 g repairs (which also seems like a lot, we offer 50 g but we're also a social guild), but I'm curious, because at least the 7 hc dungeon challenges should be covered by your regular raiders for VP cap, or do they all prefer doing dailies for cap?
To fix it I would just remove the repair for the socials, they may be unhappy, but it seems your main focus is raiding with 4 raid nights, and if the social part is compromising the integrity of your raids the choice seems fairly easy to cut the perks of being a social.