I should think it would be okay. It's easy to be sniffy about budget gear, but the fact is my tandeming pals went round the Outer Hebs with a £20 Eurohike dome and did okay with it, not dissimilar to the Eurohike dome being used by a chap just finishing a Lands End to John O'Groats we had a natter with at Thurso.
An acceptable tent pitched with care is usually at least as good as a notionally great tent pitched badly, and cycle camping tends to keep you away from the more ridiculous pitching spots.
wary because its a Karrimor tent as they arent the same quality as they used to be
I presume you mean Karrimor in general, because "Golden Era Karrimor" were never in the tent business IIRC. It should probably be okay amongst £100 tents but it's a pretty heavy beast... I'd be inclined to look at, say, Wild Country for a good compromise between price and quality.
If a jacket is wetting out you can wash it in a DWR re-proofer. Rather cheaper than replacing it (in fact see below and note Patagonia say you can expect to be doing this...)
It's perhaps worth noting that a thinner material will, if all else is equal, typically wet out more readily than a thicker one. Also the case that the drier you keep the jacket the better it works for breathability: if it's not too windy and you don't need your hands a brolly is a wonderful thing for keeping ypou dry.
Patagonia stuff is good but you can't break the laws of physics and there's no particular reason to expect this to keep you significantly drier than the Drillum. The DWR is good but again nothing's perfect, and this is what Patagonia say:
Most waterproof/breathable shells on the market are originally treated with a Durable Water-Repellant finish (DWR), which keeps the outer fabric from becoming saturated so that the breathable barrier can do its job. This coating needs to be replenished once per season, or more often if the piece gets a lot of use or washing. If water is no longer beading up on your shell, it’s time to put on another finish. Our favorites are Grangers products, though there are many good products on the market. Whatever you choose, be sure to use a spray-on for two-layer garments (with a hanging mesh liner) or a wash-in for three-layer garments (with an interior fabric protecting the barrier). If the situation does not change, please send us the garment and we’ll take a look (see Returns and Exchanges).
The Torrentshell is light and it's 2.5 rather than 3 layer means that much less overall robustness than 3 layer. Though the "Plus" has heavier shoulders and sides that's a relative thing, and if you want a more robust jacket then you're realistically going to be looking at 400+ grammes, probably 500+.
One thing that generally miffs me about Patti's waterproofs is the hoods aren't usually wired. Shame, as other than that I think they're very good.