UK Travel

Hello, Im going to the Uk on vacation and had some quick questions.

1. I planned on getting a Travel Esim to use while their for data only, does anyone know if I will receive my SMS text messages and be able to do WiFi calling?

2. If I mess up the E-sim process or at some point mess up the settings, Total wireless doesn’t bill additional fees later right? The maximum I can pay is my normal monthly amount no surprise international Roaming/text/call charges later?

thank you very much