Re tyre choice, yes makes a massive difference. I didn't like the dunlops that came with it (they were on the tester too), so negotiated a swap at delivery. A softer compound makes it more refined on motorways, sadly our UK motorways are very roughly surfaced, especially the ones I use, so don't expect miracles. Tyre pressure also makes a bit of a difference. The F sport is on 19" wheels and harder suspension even in comfort mode. If you value comfort, then base, premium or Takumi. Although the latter will hit the 40k limit.
Yes, I found the premium edition the sweet spot and good value for money. Some pretty good deals on carwow shy of 32k with metallic on premium edition.
Re overtaking, the eCVT (not belt driven) takes some getting used to. Yes, pedal modulation definitely the way to go. Paddles or + - on gearshift not very helpful, best to let it do its thing.
See this for how it works if you're a geek like me (yes I know it says RAV4, same setup p710). For me it made a difference on how I drove it when I understood the internal workings of the thing.