I know there are rules regarding Muto Vim effects being placed in items (namely that the only time Muto Vim effects can be placed in an item are when they are altering effects also in the item... unless you get the Consummate Talisman mystery virtue)... but is there similar rule about Rego Vim effects?
Namely, I was wondering if you could instill a Rego Vim spell to sustain the concentration duration spells that you cast. Additionally, if the effect is being placed in your talisman, could you instill a ReVi sustaining effect at personal range that would effect the spells you cast?
With regard to personal-range - that doesn't work with Rego Spells being cast by the caster. Maintain the Demanding Spell (as an example) is touch range, and that's for targeting your own spells.
Items which are going to perform similar roles will need to target a spell cast by someone else, which means they need to be voice range. As for a talisman being used, I'd discuss with the SG whether or not a talisman counts as the magus for the purpose of targeting spells (i.e. can be touch range, can use the more economical base effect). I'd personally lean towards yes, but it isn't explicitly stated anywhere that I've found so it's ultimately a SG call.
Nope. Your talisman is not you, despite the close link.
Minimum Touch range. Based on MuVi guideline it has been suggested that it should infact be mnimum Voice range.