Seat reservations are not required on any British trains except Eurostar to Paris, Brussels, Amsterdam and sleeper trains.

The note on the planner is not accurate.

You can however reserve seats on some routes, this can be done for free by creating an account on www.gwr.com (one of the national rail companies).

London - Glasgow would be a good idea to reserve, Glasgow - Inverness also if they are available.

Glasgow - Edinburgh not available

London - Oxford, available on some trains

London - Dover not available

Bakewell does not have a station. nearest is Matlock which has regular busses to Bakewell, bus not included on pass. Reservation possible on London - Derby part of that trip.

For Italy I wouldn’t wait until the night before but generally trains do not sell out far in advance, there are exceptions though with local holidays and events, etc.

For F1 events yes definitely book travel, these have very high attendances. Look at official sites and fan sites for advice on getting there/back. It’s a long journey from Vienna, over 2 hours to the nearest stations Zeltweg or Knittelfield, neither are that close, add time to get to the track and get in… You might want to look at staying closer.

@Al_G Thank you so much! What is the latest you recommend to book seat reservations? I will be in Rome for the first week of July, so I still have a good amount of time but do want to try and have everything ready before I leave. Vienna was the only place I could find housing but is a place that I wanted to visit, hence why I’m staying there even though it’s a decent distance from Knittelfield. I have seen other people discuss staying in Vienna and going for the F1 race and didn't see anyone complain about it, so hopefully it’s not awful. 

If you want to know whether seat reservations in Austria are advisable, then either look up your journey on tickets.oebb.at (there will be a warning if ÖBB recommend one) or provide the exact trains and travel dates, so people can advise.

@rvdborgt Thank you! I’m looking at one of them right now on ÖBB, I don’t see any warnings saying they’re recommended. I’m going from Vienna to Knittelfeld for Formula 1 from June 28-30, so I wasn’t sure how a sporting event might affect seating/trains. I was also thinking of getting them just in case too.

Definitely busy then. If you'd like a seat book one.

There might be extra trains too, I haven't looked.

I would definitely reserve ASAP, European F1 races have huge attendances so it’s a good bet that all public transport will be very on those days.

If you go through the reservation process on OBB you can see a seating plan showing how many spaces are currently reserved.