I've played three priests and
1. 19+ strength? For an amateur priest? Its hard to attain especially if you're a newb. Why? Because strength isn't exactly something a MAGE will be focusing on. Also, strength mods are relatively difficult to come by. The rings I'm thinking of you need flight for. The neck items I'm thinking of you need to actually kill the creatures for. If you're a cloth-armored priest, thats difficult.
2. Sorceror to resize. I don't know about you, but I've seen very, very few of these lately! And I've asked. OH HOW I'VE ASKED ICLY!
The flamestrike idea would be fantastic. Shamans I find to be much easier to level since they're 1. light armor and 2. can take the damage.
Priests, especially those in the cloth faiths are incredibly difficult to train. I've always had to find someone to take the time to take the attacks (pets die
even when you heal them with your cure light). You want to cry up until journeyman.