Just remember the life of a 10 dollar fish is just as important as a 50 dollar fish. I would slow down a little and wouldn't add anymore for at least 3 or 4 months, maybe longer if you can help it. Lawnmower and scooter blennies can be very difficult to keep and will starve without special care. Lawnmower needs lots of film algae which you have right now but if you add 75 snails you won't have for long and it is hard to get some lawnmowers to eat prepared foods. The scooter blenny eats so slow that other fish will keep it from getting enough food and with a tank that hasn't been up that long, you won't have enough pods to sustain it, which is what they prefer, and what they should have in their diet.