I think you'll find it works a lot better once you learn how to use it and find a media that works well in your application. I have an IR SS-3L, which is a 3HP single-stage compressor. By my estimation I've run about 5 tons of Unimin Industrial Quartz though that little farm store pressure pot.
Completely stripping the Do-All V-36 of four coats of paint, including all the interior nooks and crannies by sandblasting took around 24 man hours. By commercial sandblasting standards that's slow with a capital S, but it was faster than using a chemical stripper and a wire brush. The point is, your setup will work fine within it's capabilities.
Here's what it can do:
After finding some suitable abrasive for your work, the first thing to do is tune up your pressure pot. There's a valve underneath it to regulate the media flow and a second valve after the water trap on the back to regulate the air flow though the venturi. Set the pot pressure at 90PSI and open the air flow valve fully. Close the media valve completely.
Now, open the nozzle valve and point it at a workpiece. Slowly crack the media valve on the venturi until you hear a change in pitch from the air exiting the nozzle, then crack it just a little bit more. Too little media reduces the cutting speed. Too much media also reduces the cutting speed. Experiment to find the optimum location of the media valve for your application.
Make sure you're using the correct nozzle size. My nozzles start out about 3/32" ID and I find that size about right as it allows the compressor to hold approximately 75PSI during prolonged work. As the nozzle wears air consumption will rise and if you're compressor limited as I am, the pressure at the pot will drop. When it does, take a break for a few minutes and swap nozzles. The short style nozzles I've been buying are good for about 8 hours of continuous blasting.
I think the setup you have is fine for what you want to do. You just need to spend a little time tuning it up and optimizing it for your work.
A word on abrasives:
I like silica sand. I use it by the pallet load because it's really cheap, easy to obtain and it cuts fast. However, the same thing that makes silica a great abrasive also makes it a health hazard. Respired silica can lead to silicosis, which is not a trivial health problem. OSHA does not recommend anything less than a supplied air breathing system for using silica outside of a cabinet, which is what I use. Dust masks and common respirators DO NOT provide sufficient protection according to OSHA. Other abrasives are capable of causing similar problems, however their mode of operation is different.
It is generally good practice to pipe the exhaust from a blasting cabinet outside or recirculate it though the cabinet. Think of the vacuum as a dust pump. Not everything is captured by the vacuum's filter and what isn't captured is blown out into the shop in a big cloud. Most of these particulates are too small to see, but not too small to cause damage.
..it was all I could think of..
Definitely don't want to since it would be such a hassle, and money lost from delivery, etc.. But I'm not gonna hang onto something I'm not totally pleased with..