Depending on resources ($$$$) and time available, the best course to find the problem would be a top tear down in my opinion. Thats of course after doing a compression and leak down test. -dontchya just hate peeing into a headhead?- lol Anyways, the white whisps are definately moisture and unless they clear up almot immediately then they are coming from inside. Could be as simple as the start of a headgasket going south or as bad as a crack or corrosion infecting the head casting. Which isnt all that uncommon on Toyotas. <img src="/forums/images/graemlins/rolleyes.gif" alt="" />. The rough running below 1000 RPMS combined with the steam output leads me to think its one of those two mentioned. BUTT! With the blue smoke (oil) and brownish discharge (ucky word aint it? <img src="/forums/images/graemlins/barf.gif" alt="" /> ) then you have something else going on in there as well. All the symptoms can be related to the head or head gasket though. Other sources for oil burning: Valve stem seals and worn rings. Brownish smoke is a new one to me though. Do the compression then if capable perform a leakdown to see if you'll just be doing topend or an R&R on the whole engine. Trick is to follow some advice a wise man once told me. "Dont schidt the small stuff"...key here is the engine is running and theres no signs of intermixacion of coolant and oil. Another tid-bit from that same wise man was "You dont take a dump without wiping your arse do you"? Meaning..get in there and fix it right. lol Okay so that dont really apply here. You are better off getting into the engine now though before continued running worsens the problem and causes internal damage.
~Darin <img src="/forums/images/graemlins/baby.gif" alt="" />

PS-If this is really confusing and kinda in left field...just let me know. Its Monday and my brains are still at home.