Bigger tyres

You ask if they will stress anything, yes they will ,everything you mentioned but minimal in my opinion. There must be tens of thousands of Hilux utes on 31/10.5/15 tyres ,bit smaller than yours, maybe try 265/70/16 instead. You dont say if yours is a diesel ? it may struggle with the big tyres on . The FC II are not good on a wet road, have you had a look at Kelly Safari TSR. Sorry if it spoilt your plans , you could just about put anything on your Hilux , I have seen them with 33"diam tyres on doesn't seem to stop them.

Check the offset & see if they are going to stick outside your mudguards mate.
The number of tools you see driving around displaying their ignorance with their tyres outside the guards is amazing.
Putting a set of mudmunchers on that poke outside your car body is not only illegal it shows a total lack of respect for other road users. It helps throw even more stones & mud into the air. Even helps to break your own windscreen & rear view mirrors.
If you are going to have the tyres poking out you should get the whole set of accessories. That includes a dog cage, at least 2 of those dog collars for piggin hanging off the cage, 1 broken headlight, 1 broken spotlight, multiple dints, lousy paint job touched up with a spray can, wife basher singlet, pair of thongs for dressing up, a bundy bear sticker stating that you are a rum pig & one middle front top tooth missing.
Don't worry about the huge volumes of extra mud they throw up the sides of your car because bogans don't wash their cars anyway.

By fitting those tyres you are unlikely to cause any serious component failure, but what you may do is increase fuel consumption by 10 - 15%, & loose acceleration due
to a larger rolling diameter.You will go faster at the same revs but use more fuel to get
to that speed. Speedo reading may also be innacurate. Your insurance co may get
narky as well if you dont notify them of fitting non standard equipment. I dont know what you expect to gain, but the upside isnt great, might look better, but little
practical advantage. That doesnt explain why heaps of hilux get around with big
wheels & rubber does it? Ask some of them. I put them on mine for soft paddock
work while spraying..less bogging, no other reason.cheers......oldbaz.

Thanks for all the info guys. I am going to fit sr5 flares etc to keep it all legal. Would it be more appropriate to go a 31x10.5x15 over the 265x75x16? Will this be a lighter tyre?
Will my fuel consumption and excelleration really be effected that much?
And fatso, theres nothing wrong with bundy rum haha!
Cheers guys