As far as I can see, if an aircraft is out of trim, then you trim it. It should be an automatic response. You will never manage to fly an ILS down to MDA unless the aircraft is in trim. The only time I don't trim is in turns (because the aircraft will then still be trimmed correctly when I roll out) and when I want a very short climb or descent followed by level flight (eg when changing from, say, 3000' on regional QNH to 3000' on aerodrome QNH).
Agree fully with QDM re learning at short fields for two reasons:
1. Its easier to make the change short-to-long than vice-versa.
2. You get practice at making go-arounds so you learn as second-nature to make a decision on every approach... are you going to land or are you going around? I think some people go through the far hedge because it never occurs to them to go-around.
I also agree with undertheweather that most circuits flown at airfields today are far too large. Sometimes this is necessary to avoid noise-sensitive villages, but often it there appears to be no reason other than a CFI once drew a particular circuit on the map. Perhaps its to give students "thinking time" during the circuit. I don't know.
I learnt at a small airfield and we weren't allowed to do touch-and-goes, plus the circuit was extremely large (for valid noise reasons). However, it took me a lot of time and money to learn to land because I only got four landing in each hour's lesson. At another airfield with a smaller circuit and touch-and-goes (plus a longer 418 metre runway) I could do twelve landings in an hour. What I am probably saying is that the optimum is probably to have a runway that is short, but not too short and a safe tight circuit. Pity we have to live and fly in the real world !