You can't set a hotkey (as far as I know), but Tokenmod can probably do what you want. Access to the api (Tokenmod is an api script) requires a pro subscription though. With tokenmod, you would likely create a collection of commands, set them up as abilities on a character sheet for api commands, and then create a chat menu to display the list of commonly used commands in chat. So, you would select however many tokens you want to set sight/markers/whatever, click the token action you have set up to bring up your menu, and then click the command to have whatever applied to all the selected tokens. It can do a lot more than set markers though. .