Yes, Chinese algae eaters are a lot of trouble. They stop eating mainly algae once they reach a certain size (which is large for most tanks) and become rather aggressive toward tankmates.
The oto catfish is a good choice for moderate algae control. But they only eat brown and green algae, not hair, brush, dot or blue-green. They're docile and small and most people find them to be very attractive as well. I have four of them between two tanks.
Then there is the proper algae eater, known as a Siamese algae eater or SAE. Rather than being a suckermouth so to speak, this is a cyprinid, akin to barbs. This guy is rather rare and difficult to find in most pet shops. Not to mention that the flying fox, a similar species, is often sold as a SAE. The flying fox will eat algae, but not as much as the SAE. The SAE will consume green, brown, and hair algae generally. If you're lucky enough to find some they will be perhaps the best fauna for algae control in your tank.
There are also algae eating shrimp, such as the Amano shrimp. You'll need a lot of these folks to make a dent in any algae problem you might be having.
Naturally the best way to stave off algae is prevention. Manual removal (cleaning the glass, scrubbing off decorations after removing them) is effective, but will not eliminate the source of the problem. There are many threads that cover this, so I'll leave it to you to search for them. Basically you'd have to reach an understanding of water chemistry and lighting.
Consistent water changes are a good place to start.
Lastly, in regards to the film at the top of the tank, I wouldn't concern myself with it unless it's looking really serious. That being the case, you should seek to find out its cause. It could be that you're using a dechlorinator with aloe vera added to it. Maybe you're overfeeding. Maybe you aren't doing consistent water changes. Maybe you're overstocked.....
