So you got the new H2O Racing, lucky you are I was planning to get it too, but after me and my wife we both lost our jobs in Dubai, the life became not so easy, and no new watch purchase for now... Anyway It is life.
Ref. your above points, for 1. I can just confirm you that ALL the H2O watches I have purchased came ALWAYS with 2 Hex screw drivers, yes you are correct you need 2 screw drivers to be able to remove the lug screws. Also if you received only one screw driver it is not correct, I will suggest you to complain H2O and to get the missing one. Saying that it is really standard hex, I am personally using small Hex Allen keys that I put in my wallet for changing straps outside, it cost 1-2 USD ;)
Interesting your 2. point, Your Kalmar 2 Racing, is having the new Kalmar 2 case, which is supposed to be better and an evolution of the old Kalmar 2 case, the crown protection is improved for maximal protection, and much more space at the lug sides to be able to put Nato straps, that I cannot put on my old K2 as not enough space, saying that I am not a fan of Nato straps, indeed I ate them LoL... Below a link I found from another forum showing the case differences between the old K2 case (like mine) and the new K2 case (like your H2O Raching): https://watchintyme.com/index.php?threads/h2o-kalmar-8000m-10year-edition-update.734843/
I just checked on my Kalmar 2, if I remove the strap, you are 100% right the internal side of the lugs are quite sharp, but not the external sides which are smooth. Notice that I have checked on other watches (Non-H2O) it is a bit the same, even the small Cartier of my wife is having internal sharp lug edges ; I believe CW / Rolex / Omega with thin lugs are having much more smoother edges. Saying that I am not using thin Nato, I am only using thick straps 4.5mm - 5mm and some 6mm, then the problem disappears, the strap is at the level of the edge and when I pass my finger on the lug edge, I do not feel anymore the sharp edge ;) So I am afraid to say that H2O watches like thick straps
Enjoy your K2 Racing, please when you have time make me some nice photos of the dial with the left/right perlage, I love it