the smoke on start up could also be valve stem seals which stop oil leaking down the sides of the valves into the bores when stood , then on start up it burns it off straight away. i had the oil coming out of my dumpvalve as well sometimes if you have a breather system the oil goes through the breather pot down into the metering head and gets sucked through and blown out the dump valve , if you take the boost hose off that goes to the metering head and look in the bottom you will find out if there is oil there this is the problem.The oil filler blowing off could be the breather pipe that goes from the rocker cover on the right hand side to the block at the back this could be blocked and the pressure builds up in the rocker box and blows the cap off. Hope this helps im no expert just whats happened to me try it and see stem seals r much cheaper than a turbo