hmmm

-first 30 seconds: is the buzz coming from under the car or from the engine bay? that start-up buzz could be the stock converters headshields rattling due to fast idle. OR it could be the ABS pressurizing.

-ABS light: can be on due to ABS unit failure, ABS sensor failure, or ABS computer failure. you will have to pull the ABS codes the same you would pull the ECU codes.

-Startup problem: replace your fuel filter, plugs, plug wires. if that doesn't do it, get ready to replace your distributor cap & rotor. then it can go onto ignitor and/or coil.