You did well to leave the Ensolite in place. Its sound deadening and insulating properties cannot be easily replicated with any other material. Clean it well, glue any loose spots, remove the T-molding, and caulk the seams along with any other voids. Then...
You can prime and
paint for a smooth, wipeable surface, but since you seem to want a softer finish material, I'd recommend marine headliner. There are different kinds, but some are like thin carpet without a backing, lightweight and a little stretchy, making it easier to fit the corners. Intended for marine applications, it's durable, non-absorbent, mold resistant, spot cleanable, and available in a variety of colors and textures.
Look inside a newer
Scamp to see how they lay out the pieces for a good fit with as few seams as possible.
Scamp has been using a version of marine headliner since the mid-80's, so they've had a long time to get it right.