All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
We have already issued many Fataawa about many issues which you raised in the question; so we will summarize the answer to your questions and we will refer you to our previous Fataawa.
1- Video games are permissible if they do not include any prohibition, and playing them –in this case –for an hour a day is permissible. However, a Muslim should endeavour to use his time in what is beneficial for him in his worldly matters as well as in matters pertaining to the Hereafter. For more benefit, please refer to Fataawa 86533 and 83778.
2- Marriage is the best thing by which a person keeps himself chaste, so you should endeavour to marry. If a person is not able to marry, he/she should fast. There are other matters which may reduce your sexual desire; you may refer to them in Fatwa 88259.
3- As long as a Muslim is able to reside in a Muslim country where he is safe about himself and his religion, he should do so. It might be that he is obliged to migrate from a non-Muslim country to a Muslim country, and it might be that it is desirable for him to do so according to his circumstances. If a Muslim is in necessity or in a dire need to reside in a non-Muslim country, he should be keen on increasing his faith and obeying his Lord. He should also keep company with his Muslim brothers and he should avoid suspicious places and avoid befriending dissolute and disobedient people. By doing so, one would attain inner peace; for more benefit, please refer to Fatwa 86405.
4- Submissiveness in prayer and in other matters and weeping out of the fear of Allaah can be achieved by mentioning Allaah as much as possible, being keen on obeying Him, and refraining from disobeying him. Among the matters which help achieve submissiveness in prayer in particular is to endeavour to go to the mosque and sit there while waiting for the prayer and being preoccupied by the mention of Allaah and the recitation of the Quran while waiting; for more benefit, please refer to Fataawa 83931 and 88068.
5- You should continue on advising your parents and your brothers and sisters about backbiting your brother, and you should be kind to them and advise them in a gentle manner and supplicate Allaah as much as possible to guide them. For more benefit, please refer to Fataawa 90439 and 90818.
6- Performing only one Rak’ah Witr prayer is permissible as we clarified in Fataawa 83303 and 92752. The time of Witr prayer starts from the time after praying ‘Isha until the beginning of the time of Fajr; this is something agreed among the scholars . However, Ibn Al-Munthir reported that a group from among the righteous predecessors are of the view that this is the time one has the choice to pray Witr during any part of it. However, the time of necessity extends until commencing the Fajr prayer. Therefore, if someone is prevented from performing it due to sleep or forgetfulness, until the time of Fajr started before he had prayed the Witr prayer, he may perform the Witr prayer before praying Fajr as long as he does not fear that the prescribed fixed time of the Fajr prayer is over. The Prophet said: "Whoever sleeps through Witr prayer (and misses to perform it) or forgets to perform it, he should perform it as soon as he wakes up or remembers it." [At-Tirmithi and Ibn Maajah]
7- It is an obligation to obey the parents in what is permissible and in matters that do not harm the child. Therefore, if eating much does not cause any harm to the child and what the parents want from him/her is not more than what is normal, then he/she has to obey them in this regard. However, it should be mentioned that it is dispraised to eat much and more than normal.
For more benefit, please refer to Fatwa 83282.
Allaah Knows best.