Get a new camcover gasket and sort it out. They are not dear and mine does not have any leaks at all. Failing that clean it all up and use some silicone sealant. Its nowt to worry about unless you like having a messy engine. It will only get worse.
Not if you clean everything up properly then let the silicone cure for a few hours. I've always used it and never had any problems. Also it comes off nice and easy when you need it to. Its what Ashcrofts use when they rebuild gear/transfer boxes which is where I got the tip from.don't mean to pull you up on this shifty, but silcon is next to useless with oil, there are many sealents available.
300tdi sump gaskets are a tube of silicon type sealer. It's pretty pricey though. I think it's around £20 a tube.