Scout: ridiculously fast typist doesnt generally notice commas exist or indeed ne punctuation at all (other than exclamation marks lots and lots of those)!!! all lowercase or ALTERNATIVELY UPPERCASE FOR EMPHASIS & tends 2 mkae typos and shorten words
Soldier: Types with LOTS of EMPHASIS. Sometimes When On A Massive Tangential Rant He Will Type With Every Word Capatalized Because It Sounds More Important That Way. Mispells certain WORDS but rather inconsistently. FLAMES OTHERS for not using AMERICAN ENGLISH. COLOR HAS NO U, MAGGOT.
Pyro: ᘮᔕᙓᔕ ᙡᗩⅤ૪ ᔕᎩᗰᖲᗝᒪᔕ ᕊᙓᙅᗩᘎᔕᗴ ♈ᖺᗴᎩ ᒪᗢᗢḰ ᕈᖇᙓ♈♈ᓰᙓᖇ! (̤̉ͭî̝͌̇̆̃͌ͥt̪͙̜̖͖ͭ ̫͔̏ͦͩ̄̔l̪͎̱̩͕͎͈̃͑̏ͤ̑̂͒o̲ͪ͗ͥ̍͐̎͂ͅo̰͚̜̬̳ͭ̋̊k͒s͉͕̯͋̅͌ ̺͖͍͎͈͔ͮͬ̎̊͋ͧl̥͙͇͂̄̃̾̈́̍̚ͅi͎̜͕̺͉̼͉̓̃k̲ͫe͕ ̭̗͕͔̺ͫ͋̋̏̽g̱͓͚̫̥̬ͤ̒ͬĺ̖̥̞͕͉͙ͨ̉̃i̝̇̏t̍̂ͩͦ͂c̟̝̙̮̠͕̑͒͂̍̂h̟̱ͧ́ͨ͂̑ ̝̹͎̜̗̘t̼̖͚̩̱̞͈̐̇e͍̪̜͍̙͈̿ͬ͒x̟͚̩̬̩̪̱ͪ̄̍ͭ̄̚t͖͓̲̉ͧͥ ̪̓͛t̪̞͍̯̒̿ͫ̅̀̏̃oͤ͆ ̝͌̍̒ͯͫẹ̯̘̪̣̩͊͆vͩ̋̉͗e̱̻͇ͩ̅͌̽ͩ͌ͣͅr̙̯͍̮̜̯̼ͯ̿̑ͧy̩̥̣̝̰͉̗̎͛o̱̣͔̼͚̞͛̿͛̎̋͆n͙͉̩̩̹̟ͩ̃̃͋̈e̫͔̠̬̦̮͐͋ͨ̍ͅ ̤̙͇ͯͧ͋͛ͮe̙̤̱̯͆̌̎l͉̯̖̗͔͓ͩͮ͛͊͌̋ŝ͔͔ͦͪ̔ͭe̼̩̝͐̿̐̓̅.) ᒪᗢᐯᗴᔕ Ḱᗩᙡᗩᓰᓮ ᙓᗰᗢ☂ᓮᑕᗢﬡᔕ. o(≧∇≦o)
Demoman: When sober, fairly standard. Emphasises QUITE a bit with caps. WHEN DRUNK, ALL CAPS or no caps at all. TYPNI STANDRADS DELCINE (but that's pretty standard for the whole team)
Heavy: Как правило, он типа на русском языке. hangs around forums for discussing literature. in english, lower-case and similar to heavy's grammar when speaking. MAY USE ALL CAPS IN RAGE BUT IS RARELY NECESSARY. after all, no one touches sasha on internet.
Engineer: Types crazy fast but actually proofreads (and generally uses standard English I can't imagine a point where he wouldn't)! Finds that emoticons make his posts more personable. :> It depends on the situation, though.
Medic: Generally types with correct spelling/grammar/punctuation but he's liable to slip into Deutsch Sprache (which is probably wrong I just used Google Translate; same goes for the Russian above). He himself is quite unsure of why.
Sniper: tends to type only with index fingers, but he gets by remarkably well thanks to awesome coordination. lowercase for informal, proper caps for formal. uses fragments a lot. emphasises pretty often and uses CAPS when he does. (that part is actually canon when he's writing by hand.)
Spy: Types fast, with correct... whatever language he's using at the time. He tends to hang around sites in various languages and gives out various false bits of information to avoid people tracking him down. Also because it amuses him. (Admin had all the IP addresses masked for obvious reasons, though I find it pretty surprising she might have trusted the team with internet connection at all.)
Saxton Hale: TYPES ENTIRELY IN CAPS BUT NO ONE EVER CARES BECAUSE HE'S SAXTON FUCKING HAAAALE. HE PROBABLY HAS SOME WAY OF TRANSMITTING HIS FIST THROUGH PEOPLE'S MONITORS TO PUNCH THEM IN THE FACE WHEN THEY DISAGREE WITH HIM.