That’s normal if you don’t put sealant on them. Some of the bolts are open into the lifter valley and crankcase pressure can push oil up the threads.
I use sealant like this.
https://www.ebay.com/itm/Permatex-Bo...-/163277419986
Front of pan leak can be timing cover seal or pan gasket.
Some leaks are caused by too much crankcase pressure.
A non working or missing pcv system can cause this.