Did oct. booster cause my needle/seat? Do I need any oct. booster?

You shouldn't need Oct. booster now that it is Nov.

Really though, todays 93 octane (R+M/2 method) is comparable the 96-99 octane (Research method) that our cars drank when new. Ethanol is an octane boosting additive which generally gets a bad rap, although other compounds added to the fuel are typically to blame. Ethanol does increase the volatility (Reid Vapor Pressure) and decrease the energy content slightly. Ethanol blends are nice in humid/colder climates as they will absorb some water and move it out of the fuel system (Heet and other gas line dryers are ethanol or isopropyl alcohol).

If you experienced a sticking needle/seat it was probably due to crud dislodged by the octane booster (a lot contain acetone, toluene and benzine). Run a quality (not plastic or glass) inline fuel filter, fresh pump gas and be done with it. Tune your engine for the fuel you typically run.

Do you need octane boost? Read the label on every bottle of "magic goo" at the auto parts store. They ALL say you NEED them, don't they.