Just as a community resource, I have identified two early mods on Nexus that aim to address these issues:

1. Jhaerik's Disable Reactions Mod (Avoid Unwanted Romance) - not the best option, IMHO, but there is a good discussion of modding this part of the game in the comments section concerning this mod. (Nexus is just such a great community of serious gamers and modders overall.)

2. Approval Tweaks - aims to slow down the NPC approval rating accumulation mechanics in a way that *seems* more consistent with appropriate overall pacing of the romance portion of the game. Some users have had pleasant success using this mod to curb the bugs in the romance system.