How do professionals do it? Product photography of shiny / reflective items

I appreciate all advice in advance, over the years from time to time I come here when I have a problem and always leave w/ great advice and answers!

I'm looking to know how professional product photographers shoot large catalogs of items.

I run the online division of a music store and we sell many used instruments. The pictures below of the flute in the case, and trumpet with white background are examples of pictures I took my time with, than heavily edited in photoshop (knocked out, brightened, white balanced, etc).

I took all of the pictures in the same tent, w/ the same lights. It's a large tent about 48" wide, 24" deep and about 24 inches high. I built it out of PVC pipe and use a plain white bed sheet I drape over the top and sides, and another I lay down on the surface and loop around to the front w/ a slit for the camera lens.

I'm happy with the flute picture below, but I think a professional would take a picture much closer to that without much editing. I suspect my lights are not bright enough for such a large tent.

The main hurdle I'm overcoming is the pictures where the background is visible are one-time use photos for used items. We simply cannot invest the time to crop and edit each one (we take on average 8-12 photos of each used instrument).

My goals I'm looking to achieve are as follows:

1) I'd like a way to eliminate the "clarity" of the sheet (wrinkles, etc). Suspend the instrument somehow? Prop it on something? Someway the background can be blurred out more.

2) I'm having a very tough time getting the pictures bright enough. You can see the sheet looks gray in the pictures, when I lower shutter speed the instrument gets blasted out (overexposed) yet the sheet still looks gray.

3) I saw a table that was plexiglass w/ a white backdrop, however it had no sides, top, or back, which makes photographing reflective items impossible or difficult.

I don't mind investing some money in equipment that will improve the pictures, but I want to make sure I'm not compensating my amateur photography skills by spending money.

I'm sorry for the lengthy post, I just want everyone to understand how I achieve what I do so it can be better in the future.

Thank you again for any advice.