General aviation pilot reported confusion due to the lack of movement boundary markings at TIX.

Narrative

After landing at TIX; we parked at the FBO and waited for fuel. Once we started up and began taxiing out of parking; we noticed there were not any non-movement area boundary markings anywhere around the ramp. Looking ahead; there were also no taxiway signs visible. But when we looked left we saw a black sign with a yellow 'E;' indicating we were on Taxiway Echo. We had no clear indication if we were entering a movement area; no hold short lines; and no painted marking. We contacted Ground and picked up our IFR clearance; and Ground didn't mention anything about our location or entry onto the movement area so it may not have been a non-movement area. After the flight; we looked at the airport on online maps; and it looks like there might be a movement boundary line near the Echo sign; which would mean we were not on a non-movement area. But; the FAA taxi diagram shows the entire area as Echo; which is confusing. The lack of marking can be confusing for pilots unfamiliar with the airport.