I have 2 unfinished wood (pine?) outdoor chairs that have gotten really beat up by the elements (sun and extremely dry conditions). If possible, I want to fix them up and bring them inside from now on (they are pretty comfortable chairs). They are starting to get some minor splits in them and splinter, so I need to salvage them before it's too late. I sanded down an arm last night, and the damage seems realatively superficial. I have a almost full quart can of gloss "crystal clear" polyeurethane purchased by mistake. If possible, I would like to use some of it up on them to seal them. How dark will I need to stain them so that awful yellow it turned on my last project (apparently it didn't react well with paint) won't happen? I would prefer that medium-grayish "old wood" color stain, but I'm not sure it's dark enough that the polyeurethane won't yellow? Also, is there any need to fill the splits/areas it's splitered off with the wood putty stuff, or is it ok to sand them so they aren't rough and just leave them as "characteristics" on the chairs (which I don't mind)?

Additional Details

They have never been stained/painted/varnished ect... They are completely unfinished, unless you count the gray color the sun has turned them. I know how to "heal" the splits with wood glue and a clamp, but I was just hoping I could be lazy about it :-)