Not sure about the DV of Plague Cloud but note that you need to be a Toxic Adept to learn it (SG p.87). Consider switching it to Elemental Body (Acid probably) or make sure your GM is ok with it.
I like you concept but I am not sure it is a good idea to make him a combat mage. Mage strongest point are their utility spells anyway so why not focus him on an other magic and that way do not need Initiative so badly that you have to invest into Mystic Adept. Manipulation or Health could fit well to make him more of a support mage.
Given your BOD and WIL you should consider turning him into a soaking mage. If you have access to Run & Gun buy him a Sleeping Tiger + Longcoat and some other +armor and increase your STR a bit so he can wear them without dropping his AGI . Well you can even keep Mystic Adept for the added armor and you can invest the Improved Reflexes PP into something like Increase Attribute (BOD) for even more soak dice (pain resistance and rapid healing are also pretty good for a tank mage).
Manipulation have protective spells like Armor and Physical Barrier but also some offensive power with stuff like Fling (Pretty good for throwing Grenades or Knifes without having to pick the Throwing Skill and invest in AGI) or Magic Fingers (The fingers agility are based on the net hit so you will get much better result than shooting with your 1 AGI, even with the -2 dice to sustain). Not to mention all the Mind manipulation spells (use them at your own risk).
Health mages are always appreciated, nothing like throwing 14+ dice for a Heal spell or casting Increased Reflexe/Attributes around, they lack offense in their school but nothing stops you from dipping into others. The Bear Mentor Spirit also fit pretty well your concept and would make you even more tanky.
Consider taking the Focused Concentration quality if you go one of those since it might allow you to sustain multiple spells. Tough As Nails could be replaced by Focused Concentration 4 for example allowing you to maintain an Armor spell force 4 on yourself without having to losing dice for other stuff. Also because the max dice for Initiative are 5D6 and Street sam often have 3D6, Improved Reflexes Force 4 is enough.
For your character it seems decent as it is (except for what I said about the problem of building a low AGI/REA combat mage), of course 1 DP in unarmed combat is a bit pointless but I suppose you picked it mostly for the fluff?
You can still pick 2 spells (it is Magic x 2 max) just in case you forgot, you will need to spend some karma of course. I suggest for those two : Physical Barrier which is an incredibly versatile and useful spell (stop enemies, make bridge/ramp...), Increase Reflexes your Street Sam's best friend or Trid Phantasm the all-in-one illusion spell.
Clout vs Stunbolt is an eternal argument and they both have their pros and cons. Since you are taking the AOE version as well I think it could be worth to replace Clout with Stunbolt so you have a good spell to stun highly armored targets while Blast will take down group of less protected enemies.
An extra note : If your aim is just to play a fat Mage you can pick the ADIPOSIS negative metagenic quality without using getting a SURGE quality. This is stated p.119 of Run Faster :
While these qualities are intended to be the dark side of SURGE, they can also be taken by characters looking for a little extra flavor from their character’s background
RAW, this is only true for Negative though.
