I am a new CDL-a graduate, been driving for 4 months OTR with trainer or team. Downtime is terrible and pay is nil since the miles are just not racking up. Have a chance at driving a straight truck near my home, days only, home every night. Will driving a straight truck ruin my chances for continuing a CDL-A career? Will I get credit for the hours/miles of experience with the next trucking company?

In almost all cases, no. There is a bit of a racket going on with the industry. If this class B job pays the bills and gets you home, then take it and never look back.

No, no and no. I drove as a local driver using my A for 12 years. Schneider only recognized that I had my A but would not recognize those 12 years for experience, had to do a refresher course to get hired by them. So driving a straight truck, yep, that's a definate no for it counting as experience if it's for an A position.