Looks really good for your first time.
Yep, twisting collagen casings, and keeping them twisted is a real pain. I prefer natural casings over collagen, but for the few sausages where I do use collagen, I usually tie the links off instead of twisting, because twisting them is such a pain.
As far as blowouts, as you go along you will get used to how much to stuff into the casings. Even then you will still get an occasional blowout.
It's easier to control if you have help; let someone else crank the handle while you keep the casings tight, roll the sausage as it comes out, etc.
I also do NOT try to twist while stuffing. I find it's easier to twist the links after the casings are all stuffed.
Also you may have noticed that after stuffing the collagen the outer got kinda moist. Leave the twisted links at room temp for about 2 hours. This will allow the twist to get dry some (dont worry your still safe)
Adding to what Kevin (stalag) said, that sounds fine for cured sausage, where a nitrite/nitrate curing salt is used. For uncured sausage, I let them sit in the fridge on a cooling rack to dry, if it's going to be longer than an hour.
Remember, with C. Botulinum, it's not the bacteria themselves that will make you sick; it's the toxic spores that are released if they are allowed to propagate.
Botulism is caused by the toxin released from bacteria and cannot be denatured by cooking.
I talked with Kevin about this and he meant the spores/toxin cannot be destroyed by the NORMAL way & temperatures we would cook sausage at, and therein lies the problem! To be destroyed, the spores/toxins require exposure to temps around 210° F or higher to be destroyed (think about the well known precaution to boil home-canned greens beans for 10 minutes). Sausage cooked to 210° would definitely be ruined!