Roman, your off again.
(Its Sam from Lahore/Islamabad/no mans land between Krytzistan and Tajikistan here).

This information is from late March, early April. As you know, I wasn't travelling with a vehicle and certainly I do think the process with your own wheels would be much much much easier (took 3 days for me - as getting kicked off buses by the police, having to wait for new ones to pass etc). Providing they can give you security the whole way, it would be easy to do in a day from Taftan to Quetta. I'd probably stay in Bam and leave early, drive to Zahadeen, to the border and cross. Stay at the police station in Taftan and drive to Quetta. If the road to Sukkur is open, defiantly take that as the pass (name escapes me) is quite nice.

You defiantly can't travel at night, as mentioned above (which was the problem for me, as the public buses leave Quetta in the late afternoon/early evening).

I'm not sure at what point the escort will leave you (they did not pick me up until I left Quetta). But I wouldn't be surprised if they had one all the way to Multan.

I really feel that the dangers off this road are incredibly overrated. Certainly, it does not feel anywhere near as intense as any road in Afghanistan. I've never actually heard of any traveller who has had problems on the road (other than a couple of incidents with Shiite pilgrim tour buses).

Matthew, there is no way that that border would be open to foreigners. The Makran coast in Pakistan has not been open to foreigners for quite a while.