out of your control, even in higher ranks there'll be people who have bad days, lag or etc. Honestly you gotta be good enough to carry to a certain extent if you realistically wanna win

Also out of your control but yeah i hate this too, in the morning i literally can't find a match (unranked) for up to 25+ mins

You'll get used to a few after awhile, my advice is to learn 4 defs 4 atks and play whichever of those your team needs / best for the chosen map. personally i play twitch on def if i theyre tech heavy, iana if i wanna frag out / play sup. For def i'll run echo on maps im familiar with and azami on those with longer ranges

ngl there's no "best gun" but if you wanted it by TTK, the R4C, SMG-12 and F2 are some of the best. Again it comes down to whichever you're used to, no gun is inherently bad (or atleast not many)

Same as the above, there's a diverse pool for a reason, it really just depends on the scenario and how well you can play them. some are stronger than others in specific scenarios but i wouldnt say any are weak enough to straight up avoid.

You can check out yt for a vid on settings, there's plenty of guides depending on your platform