2004 Subaru Impreza

I had my car battery changed this morning by a garage technician as it was an emergency. Right after I changed battery, my car shakes when I put in in neutual position. I went to subaru dealer. I told them we might need to reset as we just changed the battery, the technician said no right away. They checked the ignition system, said I need to change the 4 cables connected to the engine, 10 minutes after, one guy came with an estimation about $130. Another 20 minutes after, the estimation guy came saying it might be a bigger problem, I have to come back tomorrow. Today they called me saying it is the computer problem. They did road test with scanner all is fine. I just need to pay them 1.4h service about $100.00.

My question is:
Is it normal that I could not change battery outside of subaru dealer because only they are able to reset the car? Is it normal we need to reset the car after we change battery? Or it's just subaru?
Do they really need 1.4h to test and reset?

Thank you very much for any help!