possible Alternator issue?

Well, if the headlights and blower go out completely, then it is not likely to be just the alternator as Bill said; the battery would simply pick up the loads in that case. In fact, it hardly sounds like the connection to the alternator through the firewall or to the battery through the firewall.

The headlights and blower are directly connected to the welded splice in the dash harness, which is directly connected to the alternator output through the bulkhead, and also to the battery through the bulkhead, fusible link, and wires to/from the starter relay's big lug.

The welded splice going bad is rare, so the most likley thing that comes to mind at this time is a short to ground (chassis) from a chafed wire. OP, take Bill's advice and get a voltmeter and put it in the lighter socket. If a short occurs, the voltage will likley dive down really low. Also, when it does this, look at your car's ammeter and see if there is a large deflection of the meter to the 'D' side.

BTW, a short on this main power circuit is pretty serious so take action on this ASAP. It may well be something else, but don't take a chance. The other symptoms reported (like occasional hard starting) need to wait and may or may not be related.