Yeah pretty much patching a sinking ship trying to prop up a dead group, since you cant even register for GNW or get packs. At least join an active smaller group if you're able to, and TBH even the "strong" groups have slots for active players that are willing to learn/contribute, as long as you have the right attitude. Not every strong group is elitist haha.

With regards to plunders, without support just run your SS during events (save your 2 refreshes for this window), particularly sage and 9 tails events where you missing a min wont make a difference to your score. GNW is a good time too but a strong group might get a walkover or quick whitewash making this riskier.