Help! Fixed-wheel virgin

Not a neophyte cyclist - lots of bikes, lots of kms - and I've done some track riding with my club (say 4 hrs). But I've just succumbed to the shiny lure of a Bianchi Pista. Mostly planning to use it for commuting (Muswell Hill to Shoreditch and back) and general getting about town. It comes with 48x16 flip-flop (79"). I can turn that over well enough, but it seems like a big gear to head home with at the end of a long day. So, questions:

What do others use for general riding in not-flat places? 48x18 (70") sounds more sensible to me, but what do I know? That would spin out at 44kph - irrelevant on ss, but presumably fairly knee-taxing on fixed. Is there a religious rule about chainring and cog combinations that I should know, or is it just maths?

Assuming I wanted the same ratio on both sides, is there a huge difference in quality/longevity between Shimano freewheels at £30 and White Industries ones at £90? I'm not going to be doing mega-miles (have far too many bikes to choose from, in all honesty) but will ride in all weathers.

Same question WRT fixed - is it worth spending more than the £6 Wiggle want for a cog, and does the chain brand matter? I did a search and people on here seemed happy with quicklinks in 2008 - is this still true? Not planning to use this actual bike on a track any time soon, and I won't be riding brakeless.

Apols for length and cluelessness.

Both Shimano freewheels I owned reached about six months of general use before skipping, clunking and degrading then needing an overhaul. Wet weather kills them in particular. I've switched to a White Industries ENO and the difference is noticeable in build quality. If I had known this previously then I would have just bought an ENO.

I ran 47x19 fixed when I lived in muswell hill. Bit spinny on the flat but perfect for the ups and downs of the norf hills.

You will have to play a bit with gearing to understand what best suits your needs.

For instance, I live in a very hilly part of the world and find that 63-65" works best for me as an all-purpose commuting and round town gear. This is for up to 25mi per day for me. I opt to sacrifice downhill speed for the ups, which are still quite hard in many places. I spin up to 200+ rpm on the decents. I use two brakes.

70" is often a good place to start.

The cheapest track cogs are stamped steel and prone to poor finish and threads stripping in use. Nicer cogs are finely machined, more round, and last longer.

Chains. They all work. I've used 1, 8, 9, and 10 speed chains on fixed drivetrains. The 1, and 8 speed chains last the longest for me. Also the least expensive options. The SRAM PC-1 is a finw chain and inexpensive.

i find 48/19 a very good all round ratio. In terms of fixed sprockets, i have used the wiggle one mentioned for a few hundred miles now and have had no problem, but i'm sure it will not last as long as a phil wood cog for example

Low sixties in heavy traffic; high sixties Winter training; low seventies Summer fun: anything over 72" is for track, TT and silly-billies.

If flipping & flopping, a lower ratio for the freewheel is a good call: spin up the hills and coast down them.

Shimano freewheels (and chains) are the only "Big S" components I read varied reports of: there are enough well-rated alternatives that I don't feel the need to find out for myself. WI are superb (serviceable for one thing), but if the price is too strong then the Halo Clickster is the mid-price choice, or just get a <£10 Dicta or similar knowing it'll only be good for a year tops.

Stamped steel sprockets are more likely to give you jip with more chains, than something CNC (noisy, poor engagement/disengagement). Phil Wood are worth every penny and EAI a close runner-up: compare the profile of the teeth with what £6 gets you.

Quicklinks are as strong as the rest of the links and a bushed chain is preferable to a bushless one, but the cost of something like Izumi V Super Toughness is better spent elsewhere: better two cheap chains, than one expensive one (which you'll be reluctant to replace in time, in order to get your money's worth).

Thanks all. So consensus seems to be to go shorter than I'd considered. Something in the high sixties, maybe a 48x19 to avoid having to change the chainring. Might buy a few different cheap freewheels and see what works, then splurge on proper kit. Back of a fag packet says I need an extra link to go up to an 18, but I should be able to try a 19 after that just by pulling the wheel forward. So 2 x freewheels, 1 x chain to start with, see what happens. I think I'll stay firmly ss until I've found a gear that works for me.

OK, so I've gone for 48x18 for the time being, ss, and will see how I get on before flipping my flop. Next astonishingly dumb question - punctures: I added some chain tugs to make it easier to get the chain tension just so. Now I'm struggling to work out how/if you can remove the rear wheel without undoing the tugs. You can't move it forwards to release the chain, because tugs. You can't unship the chain from the chainring, because chain tension, and you can't pull the wheel out, because chain. I could carry chain pliers and split the chain, but that's stupid. I could carry a 10mm spanner as well as a 15mm and undo the chain tugs, but that seems to miss the point of having them. Just how dim am I being here?