When The Doctor travels back in time to visit Kazran in his bedroom, the TARDIS is hidden behind two large doors, with the TARDIS windows clearly visible even when the doors are closed. When he does travel back, he appears in Kazran's recording, but you can still see the TARDIS's window between the doors.
The older and younger versions of Karzan come into physical contact with no ill effects. According to the "Blinovitch Limitation Effect", such contact between two versions of the same person should result in a dangerous energy discharge.