Is it safe to assemble shishkabobs ahead of time?

adsolutely. you can marinade them at least a day ahead. But if you are making chicken kabobs and your marinade has a good amount of acid(lemon juice,wine,etc) then i woulddnt let them sit to long because they will get very tender but also dry out when you cook them. and make sure they are properly cooked

You can assemble them 1 day ahead without any worries. Any longer than that and I would make sure they were in a marinade. Also, make sure that all of the ingredients are cut in uniform sizes otherwise some things will be overcooked and some things will be raw! I like to put all of the meat on separate sticks, and then do the veggies on other sticks. Don't forget the pineapple too! Grilled pineapple is so good!

Of course, Just keep them covered and refridgerated and don't marinade the meat with the vegetables.

as long as you keep them in the refrigerator it should be fine. you cook them so there will not be any bacteria left. just be sure to thoroughly cook them!

yes just refrigerate until ready to grill

Sure and you can marinade them, too.

yes as long as you are gonna marmalade it