Are my characters marriage materials?

Harlock He'll be loyal and can be passionate, but unless you're fine with a spouse will go off for weeks to months off-planet, or spend the rest of your life drifting, his wanderlust negates his good qualities

Snufkin is absolutely not, he needs significant amounts of time alone, even at his best, he can be pretty thoughtless about the feelings of others and actively rails against a settled life.

Thomas 100% malewife, can cook, doesn't mind cleaning, and while he'll be 'you want me?' an absolute sweetie.

Soma surprisingly so! If you don't mind having to deal with supernatural bullshit for the rest of your marriage because your husband used to be Dracula and some people have a problem with that.