-If he had to wear a shirt what kind would it be?
Hm... if possible (taking "shirt" to mean "all tops") he'd prefer something sleeveless, tight, fitting to his skin. Something that's soft and gentle on the skin but also skintight for the sake of his movement.
-If Liquid were given the opportunity to change one thing about his life - just one - what would it be?
-What kind of interaction/relationship did Liquid and Big Boss have when Liquid was young? Did they have one at all?
Ahahah, oh boy, kettle of fish here. Liquid wasn't really young when he met BB; I headcanoned a while back that BB actually didn't know who Liquid was when he picked him up. He was probably encountered on the battlefield, which according to external material would have been at the age of 13 or older. He only knew him for a few months, but considering his youth was likely consumed with stories of BB IS AWESOME YOU MUST BE LIKE HIM BECAUSE YOU ARE HIS SON/CLONE/THING, he went into it with starry eyes and was... heavily thrown back to earth. BB at that time was a somewhat grouchy old soldier, after all. Disillusioned, angry at the world, and definitely not at home with the idea of being replaced by a copy of himself.
However, he was not entirely lost yet. I don't think BB actually considered him as pathetic as he portrayed; a good part of it was probably BB's attempts to encourage him. Seeing the kid's rebelliousness, he sought to try to make him do his best in the best way possible. By beating him down, he goaded him into trying his best, and also attempted to knock him down a few pegs. Unfortunately, teenagers aren't the best at logic and Liquid is a bit of a derp.
Needless to say, things got strained fast.
-What led Liquid to hate Snake for killing BB instead of happy that he was dead in the first place? Was he legitimately angry over the loss of his father, or just jealous?
When it comes to Big Boss, Liquid has many complicated feelings. Of all of the Snakes he is the only one to refer to him with familial terms, and it's likely that, as the one raised in England (and in my headcanon by Zero) he would have basically been tarred with the name of "Big Boss' son".
But when it comes to his death, things get even more complicated. Firstly, we have the jealousy aspect. To prove he's better than Big Boss, he needs to surpass him. It's... very hard to surpass someone when they're too dead to see it. On the same note, this means Big Boss will never be able to take back his words and be proven wrong about Liquid's inferior status. And again, he wanted to kill Big Boss himself.
I do think that there was some part of him that desired Big Boss' acceptance. The rejection he had from the man was initially covered up by bravado, determination, and general brattishness before eventually transcending into dislike as he grew older. There may have been a part of him deep down in the back of his mind that was truly sad that Big Boss had died - it couldn't be said that he respected Big Boss but he did respect what he did. If there was, however, it was a tiny part compared to all of the anger and hatred he felt towards him. But for the most part, his feelings regarding the man's death were tied more to his inferiority issues than anything else.
-I want to hear about Liquid's thoughts and feelings on Ocelot, Wolf, Octopus, Mantis, and Raven during Shadow Moses.
-Solidus killed Raiden's parents to raise him, right? How did he know the child would be a good fighter?
Sola-Ui Nuada-Re Sophia-Ri
-Why does Sola wear puffy pants?