What are your thoughts on these coins for a long-term spot hold?
Why not Doge? if you are for utility and real world use case, Dogecoin beats them all. Thus, most of them have already made an ATH and this is hard for coins that have reached certain highs in the past, they're unlikely to get back to that spot even as Dogecoin is struggling but it's half way there.
Indeed, it would be a serious omission if we wanted to invest in memecoin but missed out on the king of memes, Doge. But I think OP has a reason for not including Doge in the list because its market cap is too high and can't give better returns than these memecoins.
The bull season has just begun and Dogecoin is already halfway to rediscovering its old ATH. So it would be wrong to say that they won't be able to touch the old ATH, I even believe that all these meme coins will make new ATH just like bitcoin did.
Are there any red flags I should be aware of, or do you see potential in one of them?
It's hard to say because all of them are top meme coins and the potential really differs each of us. I can say that all of them have the potential but I don't like how it went for the past cycle and I am looking for profits. The profit that can be tremendous as if I've won the lottery and that's just me and it's different on your case so determine your goal.
Giving investment advice is already a difficult task, and it's made even more difficult when his list is full of memecoins. Honestly, I have no advice and dare not give any advice when it comes to altcoins, let alone memecoins. So it all depends on OP's preference because investing in memes depends a lot on luck.