Hi there! So that load doesn't seem too much for a 10 gallon especially if you stay on top of your water changes. I use this site here: http://aqadvisor.com/
to get a rough idea about how the tank and bio-load will be!
I caution the idea of ghost shrimp and cherry shrimp in the same tank together, I know some people have done it but Ghost Shrimp have claws while most other shrimp don't. They light to fight at times and the Cherry Shrimp can be defensless against them. However if you think you can handle this, then that is completely up to you. Also Shrimp have a tiny bio-load and you could literally have 20-30 shrimp in there and be completely fine, but again up to you as to how many you want!
Be very careful with acclimating Otos as they are a very sensative fish and need a very mature tank. Are you going to cycle this tank? I use this site as a guide: http://www.oscarfishlover.com/helpfu...ng-an-aquarium
I also like their picture, helped me understand.
Back to shrimp, ghost shrimp are scavengers and will eat left over food but not the decaying food. Cherry shrimp eats algae and sometimes will feed on leftovers. If someone else could recommend a good sinking algae wafer that would be good.
Your betta would benefit more from foods like Omega One or New Life Spectrum, both Betta Pellet formula. They have less wheat and grain fillers in them which makes it good for a carnivore fish like the betta! The snail will just go around eating algae and some left over algae wafers if it's still there when it gets to it.
Most Plecos get too big and rowdy for a 10 gallon, there is a Bristlenose Pleco (I have one) but it can still get up to 4 inches which is rather big for a 10 gallon. You will do fine with 3 otos, each getting up to 2 inches at most, but those guys do have a big bio-load as well.
Corydoras are half scavengers and half algae munchers as I call it, they will munch on some kinds of algae but not all of it. They also eat leftover foods or sinking bottom feeder wafers.
Basically for carnivore fish you want to find the food with the least amount of filers and more meat. And for herbivores like plecos and otos you want to find, obviously, algae wafers. I'm not sure about their content but I assume you still don't want too many grain filers as they can bloat your fish.
Oh, I have dwarf Corydoras in my tank and I love them, they zoom around getting everything clean and are hardier IMO than Otos. They only get to about an inch making them very good candidates for smaller tanks. If you can find them around you, I thoroughly suggest them! And you could have 4-5 of those in a 10 gallon, they don't have as much of a bio-load as Otos do.
Careful with mixing sand a gravel, over time the sand will leak into the gravel making it nearly impossible to siphon out unless you have a clear border somehow. In most of my small tanks which are also planted I have gravel but in the bigger ones I use Black Tahitian Moon Sand which I absolutely love. All sands you have to wash before putting it into the tank, especially if you use play sand or pool sand. If you use aquarium safe, store bought sand it usually requires less cleaning and I actually use this method here: http://www.youtube.com/watch?v=d-XB0bwtZh8
and it works great. It still gets a bit cloudy but it's so much easier to work with, just make sure you clean out the bottle thoroughly before using it.
Also that plant package looks great! Some of them like to have medium lighting so down the road it might be beneficial to switch out your lights but you won't have to worry about that for a while.
Well, I think I've covered everything so far lol, sorry for the immense amount of info here >< I tend to go overboard sometimes.