First off the stock Mazda Apex Seals can take a good deal of abuse. most natrtually aspirated models can reach 150k or more on them. they only really break when the motor gets leaned out or too much carbon gets built up.
Second off, there is no reaosn to rebuild on that short of a timetable unless it is being actually raced, or you like pisisng money away.
Oil consumption should be about a quart every 1000 miles. oil is injected into the commbustion chambers to help keep the apex seals lubed. this is part of the reason they smoke so much at startup after being parked a few days at a time, as the oil bleeds off the walls.
USe the reccomend oild, generally 20w50 or 10w40 dyno oil. synthetics can cuase problems and smoking.
Streetports can have the same lifespan as anyother motor, which is strongly based on maintance history.
Apex seals are either 2 peice or 3 peice, 2mm or 3mm and steel or ceramic. they require a rebuild to replace and run about 60$ each for stock, and you need 6. aside form compression testing, there is no way to check them, as visually the only way to see them is through the sparkpluig hole, an those are pretty buried down the side of the motor. increased oil consumption would be from oil seals leaking, not apex seals.
General maintance calls for oil every 1000 miles (check level at each tank of gas) and oil changes every 3000 miles. flush engine coolant every 24,000 miles or two years, replace the fule filter at the same interval. clean the spark plugs every other oil change and replace them once a year (which you will see why after you clean them the first time). the MOST importnant thing is to take them to redline at least once a day. serously. it helps blow out the carbon build up, which decrease apex wear. furthermore on the 6 port N/A models it keeps the 6PI sysyem actuators free, which boosts low end torque and high rpm horcepower. serously visit the redline daily, it does help the motor. avoid going over 3000 rpm untill the engine comes upto operating temperature as well. on turbo models allow for a 30-60second idle down time.
the biggest killer of rotarys is overheating. thats how i lost mine. do not continue to drive the car if the temperature guage starts to go above the nromal position. do not drive the car with low coolant either. overheats kill off the waterseals and can warp housings. if it continually tries to overheat have it fixed.
adding power depends on what you have. like all motors thay are air pumps, however they are far more effiecent at it than a piston design. mods like freerflowing exhast and intakes can net 25hp or more across all models and years. due to the exhast port location, they take ot forced induction wuite nicley, capable of spooling trubos larger than one would suspect for an engine with their displacement. naturally aspirated street porting, bridge porting and perphiral porting are the main power getters, but require a complete teardown to perform.
deserio? what year and model is your Second gen? also go vist this site:
www.rx7forum.com their second gen forum should open your eyes some.