It is useful to repeat, in Islam there is no idea of the cleric or the priest. Is it hard for many to understand this, but it simply is not existing.
AK84 correctly highlights
It is true in fact about all things in Islam.
Some people of course like to get the fatwa (an opinion) of a scholar because that is how they are, and it seems to me that converts in the west can never quite shake their orientation to the idea of religious priesthoods, but it is not necessary.
in any case it is quite common for the elderly not to perform the full rakaats.
No, this does not mean as God wills, it means If God Wills (it). In sha’ Allah. In=if.
The phrase as or what God willed is Ma sha’ Allah. What God will(s/ed). But it feels a bit strange to use it for such a circumstance, normally it is said for good things, while for bad things we say more frequently Hamdoulillah or its connected phrase.
correct.
this is the proper way to be a muslim, not those who force ostentatiously the prayer.