Uses Vodafone network. Check the coverage around the areas you frequent before buying.
If you order an eSIM, an email with a QR code will come within a few minutes.
Definition of new vs existing customer is controlled by Lyca Mobile, not the cashback provider. You can use dots if you use Gmail(support.google.com) to pass as a new user (i.e. [email protected] and [email protected] all go to the same inbox).
There is a generous 60 day window for SIM activation (applies for cashback as well), which one of the few good things about Lyca Mobile.
Previous deals have a large number of users reporting how poor the number porting process is. I would suggest you use the number that comes with it on a dual SIM phone and set that number for data usage only.
If you want to use it just for the first month and not renew at the regular price, make sure to check both the auto recharge and auto renew settings in the Lyca Mobile app or website. People in previous deals have reported being confused by this and assumed that they are the same, only checked one of them and have ended up being charged for a second month. One of them will be on by default. Make sure both of them are off.
Not to downvote the OP but Lyca is the new TPG in my experience - if all goes well then that's fine. Slightest issue needing their support - you are in for a sh*t show..