First of all i want to say I'm glad to sse your asking for player input before you do some balancing changes.
As plrimarly playing a healer some of my thoughts might be abit bias toward some classes and skills.
-It's good to see some threat changes. I'll leave the speculation out to the tanks out there to whether or not it's productive.
-War and Sin changes seen ok. Not sure of the greater impact they will have yet.
-Ranger changes see ok as well. Not sure about Recall (upgrade from Celestial Recall) removing snars.
-As everyone says, Mages need alot of love at this point. With the worst dps (of the 4 dps classes) and weakest armor they are probibily played even less than tanks at this point. With current stun machanics, the stun from Scald seems abit pointless. Would it not be better if it reduced the cast time on Boilind Blood? Or maybe make it last longer? Mages don't have any other DOT's anyway, other than from Blazing Embers. Which btw, isn't that great either if your smaming Incinerate. You will get 1 tick from DOT before it's reapplyed, So really your only getting a 10% bonus from it. An increased crit dmg might be a better use for this tallent, even if it's only from Incinerate.
-There's always room for improvement in healers. Life Breather... There has to be the worst skill somewhere and this is it. Unless it can make Resurrect instant cast no one will probibily ever put points there. Healing Touch is an ok talent though 2 points for it is alot for healer builds. Holy Vengance, not sure how i feel about this chamge. The current movement speed is ok, but no one really uses it because 1)it's pretty worthless in PVE and very few people spec into a PVP let alone a PVP healer build 2)in PVP if your being hit even running at normal speed can get you out of a fair amount of trouble, and when you can't it's because your stunned or snared and a movement increase isn't going to do you any good. As for the proposed change to increased healing power, it could be ok as well, but again, worthless in PVE as your not ussaly going to be taking hits (atleast in groups, solo play is a different story). As for PVP, it could be useful, but you run into the same problem where if your silenced and being hit your not casting anyway. I'm not sure the reason behind the change in Dogma, but if it can trigger other tallents I'll call it a win for now.
As for the other 2 questions reguarding ranger pets and medium sin armor..
Any changes to the ranger pets should consider the mage pets as well
One change i would like to see for all armor are the stats. It doesn't seem balanced when all of them have the same atribute points but medium has higher defence rating and armor, and heavy has even higher still. Wouldn't it make sence that for sacraficing armor you have have slightly higher stats, maybe not more vit, but more mana and sorc/range.
Other Issuses/Changes
8.5 sec silence with a 6 sec snar is abit op for the warsins in pvp (coupled with 2-2.5k dps) Nothing like standing there for 10 sec being able to do nothing
Give people a reason to play mages(BTW why does Ignite need to cause high threat)
Why does the Prophet tree have so many scatered points for mana regen? (I'm not going into detail about them atm)
I know 50 content is aways off, but has there been some thought on balencing for it?