#1 - No, you are only allowed one bull elk license, whether you fill your tag makes no difference. You could buy an antlerless archery tag and then buy an OTC rifle bull tag. Or, an OTC either sex archery tag and then an antlerless limited draw rifle tag.
#2 No, the bear tags that are during rifle season are the OTC with caps tags and you have to have a rifle elk or deer tag for the same season and unit. You could bowhunt Sept, and apply for limited antlerless rifle elk or deer tag (some sort of "B" tag) fora rifle season so you would be covered if you wanted to get a bear tag for the same season.
There are bear tags that don't require you have an elk or deer license, but that season is in Sept.
If you are looking for a way to stretch bow season out all fall, A plains deer tag or a Nebraska tag is a popular choice.
There are some exceptions to what I listed above, but you want to look at the regs and see what the "B" and "C" tags are for each species when you are trying to get multiple tags for the same species.