In SR3, a well known problem revolves around deckers taking up a lot of time where other players cannot really contribute. Would it be wise or possible to have other characters jack in with standard cyberterminals so they can at least participate? What hurdles can I expect?
The biggest hurdle that you'll run into is that cyberterminals are not cyberdecks. Without a Masking Persona rating to avoid detection, and an Evasion Persona rating to dodge trouble once it finds them, they have no defense against the things a decker will face. Your cyberterminal-users are effectively nude cripples walking into a warzone.
Hitcher jacks exist to allow a non-decker to see what's happening, but the only person they can interact with is the decker. As far as interacting with the environment goes, they're just along for the ride.