If you’re yanking the head on an E46 there are some other special tools and cam jigs needed to time the cams as well.
Repairing the oil filter base gasket is easier with the vanos out, but it’s not completely necessary and if the vanos isn’t leaking I wouldn’t touch it. You’d just have some snaking around to do to get everything out and cleaned up.
As far as the torx socket set there it all depends on the OD of the body to get at the headstud. A thinwall design like Snapon will fit, some others do as well. But some of the heavier built ones do not fit in the machined pockets between the cam trays and it requires you to remove the cams and crap from the head to get to the OE studs, which can be a royal pain in the ass and risky with large lift cams. With the proper tool this is not necessary and the cams and trays just stay put. All the other bolts that require this type of socket are relatively open and most sockets should fit them.