You can keep the oil in there if you are lifting the whole enigne out in one lump (ie not remving the head first an then the block). The only reson is to aviod oil leaks, thats all. Theres nothing 'wrong' with keeping the oil in it, but if its drained, then you won't get an leaks if you drop it or it turns over etc etc.
> where should i lift the 1.4spi out from?
look at the rocker cover area, you should see 2 metal eyelets (one at each corner). This is where you wrap your chain or rope and then that gets hoocked onto the end of your engine hoist.
> what size are the bolts on the engine mounts??
usually M10, but may be different from engine to engine size.
The bolts you can keep and resue (as they only torque up and not stretch type), just replace the engine mount that has the rubber moulded on it.