Tom, if those are your first attempts at domain names then you've not done bad at all. My first attempts were a lot worse, so well done.
However, for me there are a few reasons I would not register some of the domains and it's generally around 'who' would buy these domains, and the potential number of interested 'end users or resellers. Lots of first time buyers, me included, looked at Exact Match searches as the 'key' to finding good domains but you must ALSO look at 'who' you want to buy your domain once registered i.e. are you looking to resell to fellow domain name traders or an end user?
Here's my take on who might buy these domains and how I evaluate whether to purchase a domain or not:
BananaBread.co.uk: There's probably a reason this domain hasn't already been purchased. It's too specific within the recipe niche, and although you may find an eager Banana Bread maker out there somewhere it's unlikely they will pay much for it. And why would an end user want this domain?
As a potential 'brand' name the word banana would trip lots of people up in remembering how to spell it.
Value: Reg Fee. (By the way the 'Buy BananaBread.co.uk' link on Whois links to BananaBread.com on NoktaDomains????)
BestMobileNetwork.co.uk: This one is typical of an affiliate site name but what might hold me back from buying it is if I were to try and use it to build out a site then I would have to compete with all the major brands on Page 1 for the keyword 'best mobile networks'. (Although it could still be a good name for an affiliate who is just running PPC adverts.)
You might want to advertise this domain on sites like PerfomanceIN (Affiliates4U) and see if there is any interest. I would price around £50-£150.
(Your $493 listing price on SEDO is a fair end user price. I've seen much higher for crappier names.)
Widge.co.uk: Given that this word is slang for 'pen!s' I'm not a fan of this one. But you might get some 'joker' who would setup some kind of funny site on it. Not worth much more than reg-fee for me though as not enough potential buyers.
R4E.co.uk: Any reason you registered this one?
LiverpoolCatering.com: Not bad, but I'm not a fan of UK geo domains that end in the '.com', so it's not the type of domain I would buy. To me it just doesn't look/sound right.
If you look at the SERPs for 'liverpool catering' you'll see mainly .co.uk domains or brand type names.
So if you were looking to sell to an end user (And as it's a geo you will have limited numbers.) you'd have to convince any one of those to take on your .com domain, and especially if all those .co.uk will be getting their '.uk' equivalent.
Your first step should be to see if LiverpoolCatering.co.uk would be interested but I would be surprised if they did purchase it. But there's no harm in asking
If an End User were to come along you have priced it sensibly at $328 on Sedo, which I think is a fair End User price. (Considering HugeDomains have listed LeedsCatering.com at $2,600)