Wow, want4rain, you really answered pretty much all the questions...LOL
the only thing I would add is, I have both otocinclus and plecos and otos are amazing... I recently went into Ancistrus (sp??, bushy-nose pleco) they also dont grow tooooooo big and really clean well...
I would say, the rule of thumb is: one inch of fish per gallon of water is what you should aim for. So if you have a 20 GAL, aim for about 20" of total fish..
I would put some schooling fish (white cloud, rummy nose, neons...) with a pair of Kribs and a couple of Otos or Ancistrus. Thats it! If you over-populate - you will lose fish...
Also, when you set up your tank, leave it to run fish-free for about 2-3 days...this way the water gets circled around and settled, before you add anything.
Another tip would be to purchase your kribs in two separate stores, like the male in one place and the female in another. This way you avoid buying a brother and a sister (for when they mate)
All in all, I find Kribs to be one of the more peaceful cichlids out there, they are dwarf cichlids, which means they dont grow big (not like Jack Dempsey or Oscars, those get really big!!!)
Another nice fish to look into would be a Blue Ram, they are gorgeous, but they are also much more complicated...they need a specific PH level and they are much less resilient.
Babymomma, good luck, and feel free to contact me for any other info!!