how much looks, style quotient and mannerisms matter when looking for a life partner?

This is common, gays or otherwise.

I'll be quiet and listen.

Never mind about him. Look at yourself. Gay or straight, viewing people as if they were products for your consumption is a sign that you would not make a good "life partner" for any other person. Neither is the rather cold blooded way you make assessments of other people. You seem rather immature.

Or fashion/lifestyle accessories, in fact any kind of adjunct or appendage. It seems as if you are assessing people in terms of their potential to reflect credit on you, and that you think of them as secondary in importance to yourself. As long as you continue to see the world and the people in it in such a self centred way, you will probably not find a "life partner". I assume you mean a partner for life? If you mean someone who will look good next to your decor and furnishings, and won't embarrass you at cool dinner parties with their haircut or accent, then you may well find someone as shallow as yourself. Watch out for jealousies and arguments though.

"Is it important to be very physically attracted to a person for him being your life partner"? No. Be mindful that physical attraction wanes over time, and even the beautiful people become bored with each other, (e.g.Hollywood). Who's appearance improves with age? Do you really think his will?
Not to kick the hive, but is your mate of a different station in life? If you are an RN nurse, and he's a house framer, - you both probably would live in a whole different worlds if it weren't for each other. That would make things problematic, also if he must change his comfort zone so as to be in yours - that would raise a red flag.
You come across as a confident man who sees himself as cool, attractive, well dressed, and you have no worries how about how your mate's friends would react to you. Face it, you're too good for him.

I’m also going to say you’re very immature, you’re worried about what your friends are going to think? They sound like judgmental jerks, no wonder you’re still single at 35.

It depends on who you are.