Sounds like your cat is plugged. Unhook the exhaust in front of the cat and see if it’s gets better.

Your bulb has failed or the socket is burned/loose. Replace the bulb and inspect the socket for heat marks or a loose connection.

The flasher works on heat and resistance. When you remove one bulb the resistance of the circuit goes up (parallel circuit). The flasher heats up and cycles faster.

Incandescent bulbs can temporarily weld themselves back together and work for a while. It’s pretty common to be able to smack a burned out headlight and get another day or two out of it.

3.5 quarts in 7k miles isn’t that much. Most manufacturers won’t even look at an oil consumption complaint unless it’s over 1qt per thousand miles.

The VCM 3.5 does have an oil consumption problem though, keep an eye on it until you know how much it’s using. Make sure the timing belt has been serviced.