Requisites of Prayer

Dear Scholars, as-salaam `alaykum.Is it permissible for a non-Muslim to perform salah? I live in a Muslim country and my friends are almost all Muslims. When salah time arrives we enter mosques to pray.I am not a Muslim myself but I like to share this time with them. I feel at peace in the mosque and I see no contradiction with my Christian faith. God is one and His messengers have sent the same message.Since some people around me have expressed reservations, I come and ask you: Is it ok to go on or should I quit?Jazakum Allah khayran.

In the name of Allah, the Most Compassionate, the Most Merciful.May Allah's Peace and Blessing be upon you.Dear Respected Scholars,How did the early muslims from the Prophet Muhammad's (May Allah's Peace and Blessing be upon him) time and later determine the Qiblah direction? Like in Al-Madinah and other areas outside Makkah. The reason I ask is that when I am away from home and need to offer my salat, I do not know the Qiblah direction. My mother told me that you can work it out by using the sun. I also know you can work it out using a compass but I do not carry it with me, especially when traveling. It is not because I do not want to, it just nobody carry it unless you're camping. Please tell me how to work it out using the sun, it will be a great help to me. And also tell me some other methods If am not not aware of. May Allah immensely reward you.

Salamalaykom,When I first learnt to pray I learnt to say "subhana rabbina al atheem" when making rukuh and "subhana rabbina al aala" when making sujud, slightly different to what most say which is "subhana rabbiyal atheem or aala" the difference being the word rabbina instead of rabiy. similar to "rabbina w laka hamd" when rising from rukuh. Is this acceptable if I continue using this term in my prayers?JazakumAllahu Khayr