This act is Makrooh unless this is the only way of having presence of the heart (full concentration).
This person can perform Qunoot after Rokoo’ and then go for prostration without Rokoo’ and continue the prayer.
The distance between the last house of the departure city and the first house of the destination city should be considered as the distance for prayer to be shortened.
The Paternal homeland of a person is not considered as the homeland of that person unless he/she stays there continuously for a long time like one year.
Your prayers and fasting should be performed complete in both places.
It depends on the intention of the wife, if she hopes to convince her husband to return then it is not considered as abandoning the homeland and if there is no hope, then it is considered to be an inevitable abandonment.
If a person wants to stay 10 days or more in a place, in this case prayers should be performed complete and the person must fast. And if this person wants to stay less than 10 days then prayers should be performed shortened and the person cannot fast. The beginning of 10 days is from the moment of entering the destination, for example from noon of the first day of arrival until noon of the next day is considered as one day.
Travelers have the right to perform their prayers in Masjid al-Haraam and Masjid al-Nabi (a.s.) also all of Mecca and Medina complete or shortened and complete prayer is better and there is no difference between old and new Mecca and Medina.
He should perform the qaḍā of prayers (i.e. perform them again later as compensation) that he has performed completely.
There is no issue with doing this, but if that person doesn’t join the congregation before rukū‘ of the first rak‘at then his/her right is voided.
Such fears and doubts are the insinuations of Satan. Don’t pay attention to that and attend the congregational prayer continuously.
He/She should recite them in a low voice.