Tawajjo is real,same is wajd,but they are not worth the importance and attention they get.! Tawajjo is actually the use of the 'power of imagination' by Shaikh.All humans have got this quality built in.It can be activated by mujahida,zikr and meditation.when the shaikh has got such a quality,it is used for instilling some specific kefiyaat in mureed,which is actually helpful in short term,but such effects are transient,lasting only for a brief period of time (unless backed up by mureed with increased mujahida).If I got you right you are more interested in the mechanism of tawajjo,so yes,it is real,it is the power of human mind,it is helpful in short term.Again one thing should be clear.Not all people are affected by tawajjo the same way.If a strong mind can affect a Weak mind,a similarly strong mind can resist it too. If Tawajjo is used for instilling the love of Allah swt in mind,well and good,if not it is totally wrong.All depends on the intention. Wajd is a totally different subject.With continous zikr and Fikr,leaving sins and ittebae sharia,the Rooh becomes naturally more attracted towards it's actual place of abode which is Akhera.When such a clean Rooh hear the name of Allah swt and the prophet through senses,it is overwhelmed with such feelings of love which manifests as wajd on the physical body.....but that is for real Sufi,s.Unfortunately most people just fake it,which has no value.