Min/Max Boards

I don't have a lot of sources available, so don't know if this has come up anywhere else.

Share Spells (Ex)
At the druid’s option, she may have any spell (but not any spell-like ability) she casts upon herself also affect her animal companion.

The drinker of a potion is both the effective target and the caster of the effect.

So would a druid drinking a potion be able to bestow the effect on his companion as well?

I'm infamous in my group for coming up with absolutely idiotic character ideas.  Recent ones include a Factotum who acted like Johnny Bravo, and a tiefling Warmage who tried to find ways to use her Craft(knitting) in as many possible situations.  I don't know if you can crochet an effective, working ballista, but I'll find out.

My most recent one is an Assassin who knows exactly what'll happen to him in the afterlife and wants no part of it, so I decided he'll become a lich.  Yeah it's not the most optimized way of becoming immortal, but when a skeletal Whisper Gnome breaks into your house in the middle of the night and politely asks for your valuables, you don't say no.

You all are more experienced min/maxers than I am, so I was hoping you could answer some questions.  We stick mainly to Core for simplicity, but other stuff is allowed.  Complete X and Races of X are typically allowed without fuss, most others will have to be run past the DM.

-What's the best way to go about getting CL11 to make a phylactery?  Assassin stops at 10, leaving items or PrCs that advance CL.  Any good classes or cheap items to bring up my CL for the duration of crafting?

-What's a good way to hide or protect my phylactery?  I know the Genesis/Forbiddance trick, but that would be difficult, at best, to pull off without having to UMD scrolls.

-Any other suggestions to optimize it a bit?  The base is a homebrew class the DM came up with that's similar to Rogue, which I'll take to 6, then go into Assassin from there.  Assassin doesn't seem to have too much to keep me in there if I can get SA and casting from somewhere else and still keep that delectable Assassin flavor.