Thank you all for the help.
1. Yes I was wondering if there were more attractive options other than dark. My light roster right now doesn't have great synergy, and only has 2 SSR, which is why even with Sol, it simply isn't a viable choice for me right now. I do hope I get luckier with light, though.
2. Yes, my grid does still have SR weapons (3 fully broken SSR from events, 2 unbroken SSR, the rest fully-broken SR for my dark team). My fire team, I just realized, is in the exact same situation, so if I really had to switch mains, that would be my first option. I very much appreciate that you've really put thought into your advice based on my current status, though!
3. Ehh... I have limited free time and I've stuck with this account for 4 or 5 months (playing on-and-off), which I know isn't a long time compared to veteran players, and seeing as I have "good but wrong luck", I really wouldn't want to reroll and ditch this account. Besides, since I have SSRs for all elements (I forgot my water Asherah, oops), it means the next SSR I get would mean I have double-SSR for an element, whatever the element is.