Can you drive your vehicle with just front brake work done?

I have a 2000 ford expedition and got everything concerning the front brakes completely replaced. The mechanic said I shouldn't drive it anywhere until the back brake pads are replaced and the rotors turned. Which in total he said he'd charge $250... Is this true or is he just trying to get more cash? Can I turn the rotors myself? Is getting them turned even necessary? Hope a few of you can help me with this! I haven't driven my vehicle since being told this.

smoke and smell coming out of a/c vents?

I have a 2008 pt cruiser with no mechanical issues. (That i know of) anyway, I went to racetrack to get gas. As i turned my car back on from getting gas i smelled a weird smell I can't describe it . It does not smell like something is burning. I drove about 25 minutes with that smell my temperature gage is fine it isn't over heating. I looked and was completely full as well as I got on my block turning into my house white powdery looking smoke came out. I drove to the store and haven't seen any smoke but that smell is so strong. It doesn't smell rotten or gas/oil/burning. I guess more sweet in a way. Im driving with my 2 younger kids so i wanna make sure it's not a toxic thing we are breathing in. I have a 3 hour drive to go on tomorrow with them.

If you have a faulty alternator it could cause that. The battery is not charging, and eventually it runs flat. There is not enough voltage to run the ignition properly, so you loose power, and there is certainly not enough to restart.

Alternator / battery or the wires in between.

How much damage to Volvo can be done getting struck at 35 mph?

My '98 V70 was broadsided by a person claiming to go 35 mph when I'm almost certain they were going 50+, my car ended up being totaled with the other person's vehicle sustaining little damage. Can a Volvo be totaled by a car going 35?