No, it shouldn't cause any problems with the player, and yes, that is essentially the process. A few characters in a 'Notepad' file would do. The method was a well-tried workaround on the old forum for Philips discs which wouldn't sometimes finalise in the unit. In fact Loob just mentioned it the other day in replying to another post, which is what reminded me.
Is that really true? If there is just one title on the disc then a player should be able to read the IFO file and just go straight into playing the title. Otherwise with multiple titles, I wonder how the Sony keeps track of the recording sessions then - perhaps also just in the IFO file. That may not preclude it working since some players read the IFO file and will make their own basic menu from the information in there. Or can you not make +R multisession recordings on the Sony? That would be bad news, and may mean the only way out is to copy the recordings to another disc. It would appear that some sort of trial with short recordings is needed, so here's your opportunity!
Such idiosyncrasies are the reason many of us went over to the PC route for authoring, even with a more flexible recorder like the Philips. You may like to consider that: use a +RW for recording, then import to DVDMF4-DC for basic editing and authoring. Loob has a guide in his signature.