Hi mawds,
Yes, that's right - the gaskets are siliconed. You'll find all the info you need in the enigne workshop manual here
http://www.matrasport.dk/Cars/Espace/vault/JE/MRMOTL%28E%29_L7X.pdfThe two sections you are seeing are the rocker cover, then the the cam shaft bearing blocks. You shouldn't remove those unless you need to get the camshafts out. If you do take them off, you have to remove the timing belt first, as it will otherwise pull the cam shafts out of the lower bearings when you remove the bearing blocks. According to the manual, the seals should withstand several removal and refittings - and can be repaired, so you should be able to fix your problem.
However, I would personally not be too worried about a bit of oil from the rocker covers. As long as it doesn't get into the spark plug wells, I don't think it can do much harm.
I find it a little odd that you have problems reading the dipstick. Don't forget to wipe the stick well off before you dip it in to measure the oil level!
The oil level sender is designed to only read low when oil level is *really* low. It's connected on the front of the engine - actually quite easily accessible from below the car. You won't miss it
Good luck,
Anders