You're naming quite some fish there... Maybe you could look through here and help ID your unknown fish. If it is a clown > Tropical Fish for Freshwater Aquariums: Clown Loach
I have to completely second & back up all Kelly said about Bala's don't do it!
On the algae eater: does it look like this Albino Plecostomus L-083, Plecostomus | Pet Solutions
OR does it look like that? Let's be sure what you have before telling you to get rid of it.
You could add hardier plants that nicely root down into your gravel, I don't see a problem there, I'd gladly suggest some plants if you like live plants.
I'd strongly encourage you to fist be absolutely sure what you have in the tank, what may go back and who may stay. Then after that, tell us your water parameters (in this case needed would be pH & KH) as some fish require soft water, others hard water , so without knowing what yours is suggestion fish could not be so healthy.
Also you wanna stock fish that get along with one another, eg. I'd not keep one clown and cory together. Some fish are peaceful fish, others more aggressive, mixing them 2 will result in stress, stress results to unhealthiness....and eventually a early end, non of this is desired in a new tank.
I'd say determine all this first, then inform yourself, gladly with the help of the folks here, which fish would go well in your water & current stock and then with the knowledge you have go shopping.