To many options for sick fish

Question
Alright so recently MOST of my aquariums have broken out in mass desease... or should I say plague.  These would include a 5, 10 and 20 gallon.  Here are the fish and tank details:
5gallon: 1 betta, 4 glo-light tetras, 1 dwarf frog and some shrimp (set up for about 3 months)
10 gallon: 5 neons, 4 guppies, bronze cory, and some more shrimp (well established tank set up for almost a year)
20 Gallon: 1 gourami, 1 clown loach, 2 corys, 1 young pleco, MORE shrimp and several neons and cloud minnows (Fresh new tank... read below for details)
**ALL tanks have plenty of plants**

Now before I begins to list the mass contamination I'd like to tell you that my 20 gallon is under a lot of stress right now becuase they were in an emergency and removed from that tank and plopped in a freshly set up 30 gallon becuase yeast got spilled into the tank and I had very little options.  After I cleaned the tank and let both tanks sit for a couple weeks I put them back in and it was only until today that they all started breaking out with stress related diseases.  (which isn't surprising)

Now for the illnesses.  So I take it all my 20 gallon fish are suffering from stress right?  The gourami has ich and the clown loach has grey patches (not spots) growing on his fins and body.  They both are rubbing up against objects too.  There is ALSO a lot of algae in the 20 gallon becuase its near a window.  I remove the green algea almost every day off the plants but it just regrows the next day.  I am currently treating the tank with both fungus and ich medicine but I don't know if that will help the loach.

Now for the 5 gallon.  Yesterday when I was moving all the fish to the new tank i noticed that one of my glo lights was having great difficulties keeping level in the water.  He had blood forming at the anus and I knew it was too late for him.  What I need to know from this is if the other fish in the tank are at risk and what i should do.

And FINALLY the 10 gallon.  All the fish in that tank have been rubbing up against everything for quite some time.  Is it the water quality thats making them itch or something else?  Also in the past 2 months I have lost an otto and peppered cory for no reason at all.

All these tanks seem to be suffering from very similair causes and its probably been spread due to my ignorance of using the same nets.  To me they sound like parasitic symptoms but the question is what medicine is out there that wont harm my shrimp?

Now this is a lengthy question so I hope it isn't too much for you.

Thanks a lot!

Answer
Yes Mike, that was VERY lengthy question. ;)
I will try to remember as many details as possible to help you, but I think that the best result possible is by you doing some research on the nitrogen cycle, fish illness, and fish diagnosis. All you have to do is type those into a search engine, and then make yourself read the info given to you by several different sites.
You really should learn more about the nitrogen cycle, I think that will help you a great deal. You should not be adding a great many amount of fish into a tank at once.
Now, it does sound as though you have some sort of parasite. Any anti-parasitic food and/or medication should help. Mardel is a great brand.
When you added your plants, did you soak them in a 1 part bleach/9 parts water solution and then rinse them off before putting them in your tanks? This is the best way to prevent parasites, as many parasites do come on plants. And Ich is also a kind of parasite that is sometimes introduced by new plants or new fish.
Separate your fish into different tanks based on what symptoms they have, and treat accordingly.
If you want that one tank to stop growing algae, you'll need to move it away from the window. Otherwise you may as well give up - it won't stop growing. And adding an algae removing chemical to your tank will only kill off what little beneficial bacteria you have in the tank and possibly be detrimental to your fish.
Your shrimp may have to be placed into a tank all by themselves where no one is being medicated for a while.
As a side note, cory cats are schooling and need to be in large groups (at least 6) so you should think of some way to get him friends without overstocking any of your tanks or possibly returning him.