Question about Tacx Flow Smart

Venu 2S does not support power meters or smart trainer control and is therefore of limited use.

The subscription is required for Tacx video rides (with the exception of some free rides) and Tacx training plans. Both are very good and worth paying for, but you can get free training plans on Garmin Connect and free rides to YouTube videos (without incline simulation, but maybe you don't care anyway if you're looking for training plans).

i can't answer question 1. but it makes sense logically.

question2 does: there are various programmes for riding through landscapes. garmin has its own with tacx and then there are other suppliers. there are vouchers for various programmes to try out for a month free of charge. there are annual or monthly subscriptions. i wouldn't know how to use it without the programme.
it's a lot of fun to ride/train through the landscapes of different countries alone or with others.

Unfortunately, I can't answer the question about Venu.
However, the trainer can be used with Garmin Connect without a plan.