Tissue paper w my kits?

No, no, no, you guys have it all wrong.  When you open the box and find your decals misprinted or out of register, the tissue is there to dab your tears and blow your nose.

Yes, it is protection for the decals to prevent abrasion.  Some mfgs put some sort of low tack adhesives on corner or edges of sheets so you need to pull the protective sheet off. Really high quality kits may package decals in a seperate vinyl envelope.

Is it the same size as the decal sheet. A lot of kits have some grease proof type paper which protect the decals.