Okay this guy has a 1998, WHY are you telling people with 92+ civics to go to the pre 92 board!?!?!?!

Edit: i forgot why i was even posting, i had this SAME problem in the steps you did, mine ended up being a bad battery connection on the battery istelf. it was worn pretty bad for whatever reason and became loose. If that isnt it then i'd suggest digging into the engine. Also mechanics are good for doing actual work, but more likely than not, they usually go a little overboard with what is wrong. Get all your info and check all areas you can without paying anything first like the one i said, or checking your grounds. Only then, again, would I look into it being a serious problem.