Malakite, from my limited understanding, tri shoes might give you colder toes due to their design but when it warms up (depending upon where you are & where you ride) that might be OK as your feet won't overheat.
Running socks should be fine. If it's a bit cold then you could try 2 pairs. If your feet warm up part way through the ride then it's obviously easy to take them off. If you have good running socks then it might be worth getting some cheap-ish cycling socks so that you don't ruin your running ones.
Tops - well, you can get regular cycle tops or tri specific ones (sometimes referred to as monacos). The monacos are designed for running in so the zip will be lower, they won't have sleeves but they tend to only have 1 pocket in the back. For longer training rides, use a regular cycle top as you'll have more storage pockets. You can also get short or long sleeve.
You will find that most cyclists love talking about their hobby so never feel the need to excuse yourself for asking questions!
Alan, following this thread with a bit of interest but too far away from Liverpool to know what's going on. Have LCC come up with alternative routes so that the race can finish somewhere in town (Strand always struck me as as good a place as any to finish) or do they want to re-route it to Sefton Park or elsewhere?
I'd love to say that I can't fathom the response of LCC but a lifetime's experience of that shower (regardless of which political party is in the Town Hall) tends to demonstrate that they can grasp a defeat from the jaws of victory regularly.