What is with you? Sorry dude no offense but it seems you have no idea what you are doing. You keep asking questions about mixing species, "setting things free" and "rescuing" things.
1. Turtles need filtration! Does each pond have an properly sized filter? Yes its obvious in the wild ponds don't have filters but does yours have the perfect amount of plant and fish life to sustain relatively clear and safe water?
2. If you take ANYTHING from a person, as in it was a breeder or a pet, you CANNOT allow anything to happen to it. This means it cannot live in an open pond outside, where you "hope" it won't run away. That is irresponsible. Do you think some square fencing is going to protect stuff from raccoons? And other wild animals? Who would give you an animal knowing it will be living "free" as you put it, even though thats not safe, not possible, and not o.k.?
You are talking about putting RES in with wild fish you have caught which are chuck full of parasites. You are talking about keeping frogs with RES. RES will murder frogs if they get the chance. Not to mention they are very dirty creatures, and you need some serious filtration to keep things clean.
What you need to do is stop trying to adopt things and catch things until you have more experience with captive bred speciemens. Maybe after a few years of working with aqautic turtles or reptiles you will learn that a TRUE set up like you are talking about will take YEARS of work, won't work the way you describe it, and will take a huge truck load of money to do properly.
This message is not meant to offend you, but I really feel you should enjoy the herps you have now, don't get any more and start doing resaerch because you are really far off on some of your care ideas. Good luck!