It is different for an investor than a typical owner occupant purchase for a primary home. For an investor, there is minimal, if any, emotional attachment........It is simply a business transaction. The numbers make sense, or not. An investor does not get emotionally invovled in the process, and moves in and out of a deal quickly. For an investor to make 10 offers, the process is simpler and far less draining than an owner occupant trying to decide if this is "their future home."
I work w/ investors who will make these high volume of offers, and the process is much different.
For the typical owner occupant, I see most successfully going to a closing with less than 3 offers, but I have seen more. From the list of repair items detailed in your prior inspection reports, make a list of things to visually inspect on a property yourself before entertaining a purchase offer. While your visual inspection is not meant to take the place of a professional inspection, a thorough walk through will point out some more obvious problems that you can address before writing a contract.
Sorry to hear you have been on a roller coaster. Good luck.... Also, you might consider focusing on newer homes.
Good Luck and try to have fun. The seller needs you more than you need them.