Alright, more basic questions from another newbie. Sorry to all you pros out there, but I got to start somewhere!

I went ahead and permanently set up my darkroom in the pantry over labor day weekend, and have been having a blast printing away (only B & W). Thanks to all of those who helped give me direction on this topic in a previous thread (See "Help w/ darkroom decision & safelight" in darkroom disussion board).

Got some new questions. My chemicals are still good (and they are currently sitting in their respective trays with tin foil over the top). I am hoping to do some more printing over this next weekend and don't have enough storage jugs at the moment for these used chemicals.

Here are my questions:

Is it ok to leave the developer, stop, and fixer in their trays for days, weeks, (or even months?) -- having simply covered them with tin foil?

Will they "spoil" sitting like this? (The pantry stays between 60-80 degrees (F) depending on the day).

Of course I am concerned about these chemicals hanging out in the pantry where we keep the Cheerios, cooking ingrediants, etc. as I can smell the vinegary stop bath. Is having them sit out in these trays a hazard to my health?

Should I never do this and always put them in my storage jugs (most likely well-cleaned plastic milk jugs as I am still poor)?

All thoughts would be highly appreciated as I want to have children someday and don't want my expensive chemicals going bad.

On a second topic, how much use do you typically get from a fresh batch of developer, stop bath, and fixer (your run-of-the-mill Kodak stuff) in an 8x10 tray?

About how many 8x10 prints could these chemicals handle if you were using 8 x 10 trays filled with 1/2 gallon?

Is 1/2 gallon too much to fill your 8x10 trays with?

Do chemicals get weaker over time in storage?

Told you they were basic questions, but any thoughts or direction to other sources would be greatly appreciated!