rmh in an 1800 sq ft shop

Newbie here located in south texas. Yes, south texas. From early December to the end of February I'm a miserable bastard working in the shop. I work from home restoring old cars and repairing daily drivers. Any temp under 60 has me putting on my thermals so when the daytime high hits 40 out I'm ready to stay inside and forget about trying to make a living.  I love the idea of an rmh in the shop but have a few questions/thoughts that I haven't seen answered yet after stalking y'all here and elsewhere on the net. The building is 30dx60w with plans to add another 35d x 18w stall.  The plan is to put the rmh along the back wall. which is currently 60 ft.

1. Being a resto/repair shop, I have a shit ton of chemicals that put off flammable vapors. I'd like to attach the intake tube to an outside wall so the inlet air doesn't have a chance to combust and blow the shop up. a sealable door where the fuel feed is would then be used where the air/fuel normally enters. would this effect the draft? If installed, i would place the rmh unit parallel to the back 60' wall to save space. The air inlet could be as short as 4 feet long once all bends are considered. if draft is an issue, could an exhaust fan be used in the chimney as a band aid?
2. I have a pretty good supply of waste oil at the ready. I was thinking the extreme temps of the rocket stove would be perfect for burning it. I thought of placing an old air tank on top of the barrel to keep the oil warm and thin, then flowing it in a controlled manner (one way check valve) into the burn box. this may be uncharted territory so feel free to share your thoughts .
3. I thought of wrapping copper tubing around the barrel and pumping water through it to an automotive radiator. then attaching cooling fans to the radiator to aid in bringing warm air to another work area or just warming up the shop a little faster. what are your thoughts here? would it be just as effective to put a fan near the barrel?
4. Is there any negative to having 2 thermal mass' and 2 chimneys? I'd like to locate the firebox centrally in the shop, but have a thermal mass on either side, running in opposite directions in order to store more heat/ heat more area.

  Thanks for your time and thoughts.
   Paul

@Paul K: "Yes, south texas. From early December to the end of February I'm a miserable bastard working in the shop. I work from home restoring old cars and repairing daily drivers. Any temp under 60 has me putting on my thermals...."

Welcome to the site. I'm a little ways north of you, just a few hours from the Canadian border.  Any temp around 60 finally has me getting excited about outdoor projects again as anything over 75 with humidity is a real energy killer.  On the other hand, the worst days are snowblowing out the driveway in subzero weather with a face-full of Alberta Clipper ripping across the exit-way.  There's the possibility that retirement will gift me with a cab....  

The building in the photos of the thread linked here -->

https://permies.com/t/42529/rocket-stoves/FWIW-Rocket-stove-heater-concept

is ~30 X 40, uninsulated (for now), wheezy, and still with no concrete on the floor....it's a shop wannabee in the making.  But it may give you some build ideas.  I would think you could make the gas movement contained from outside intake all the way through combustion and exhaust.  My dad recalls using waste oil in his teenage days on the farm to keep warm in his shop in a manner similar to what you describe....a drip configuration.  Maybe others have done that as well here.  Also, with regard to fans, any possibility of ceiling fans to down-draft and distribute the heat through the shop?  The barrel in the configuration in the link above easily gets to 800 - 900 degrees F. quickly with cardboard scraps, then will maintain something shy of that with scrap-wood kindling.  Follow the discussion down through that thread as my build is pretty amateurish and the RMH veterans had excellent pointers.

Paul K, what you describe, it's all been done.

I have a 9 incher in my workshop. With 4 tons of mass.

http://donkey32.proboards.com/thread/1817/starting-build-220mm-rocket-double

Not saying that this is a perfect setup. But it's not too bad.

The only point i really don't like, it's the two chimneys part. Well, can be done with a flapper, which would dire the gases one side or the other. But that's up to you to turn, it etc.

With two chimneys, you would have one drawing more than the other, up to may be stalling point or even reversing the flow. That's no good.

For your size workshop, i think  something like my rocket would do. I have 113m², with a high ceiling. No insulation, and i kept +8C°, with -17C° outside. Not too bad. Things will change this winter. As i have insulated most of the upper part which will become my pad.

Hth.

Max.