Oh man, i font think u'll read this ALL 
)
Ok, i've read all these posts and came up with best ideas, if I didn't mentioned some of your ideas here, that doesn't mean it was bad, because maybe i forgot.... Ok, i dont want to forget anymore, so i'll put some notes for myself while typing:
1. Additional transport(ers)
2. Environment
3. subraces - good idea, no new races!!!
4. BC, and other units could do more stuff...
5. Terran mechanical units' explosions
6. "Watch towers"
7. Superior units
ok, sound interesting?
1. there was very good idea about zerg underground transport. also, someone said about unit for all races, well here it is:
Zerg should have worm-transporter witch would go underground ofcourse, but then all races should have something to destroy them with, but it could work out like this: When worm travels, u dont see anything except worm, so if u dont know map well, it's useless to go on unexplored area
And the only way to kill worm would be when its on surface: it could apear on surface while droping other units, and it should need air or something so it could be under ground for a limited time, also, if u would try to unborow with worm while being under the base (or unit), u would hear a sound like failing to build a base because something is in your way
. and then maybe lets say worm tries to unborow and hit cc
)) terran somehow could notice that, but i donnt know how, maybe like nuclear launch detected? - like worm activity detected or something like that
would be fun
)
ok, i wrote too much.
Transporter for Terrans: Heavily armed and i think fast ground unit witch could transport other units just like dropship. It would be great for going through tanks, cannons, colonies etc defences and droping units behind them. Also maybe this "truck" could crush small units because otherwise enemy could block it easily on the ramp or anywhere else...
I dont know what would be good for protoss. Maybe not expensive unit with normal or maybe big hp and i dont know what speed
slow/normal/fast ...but anyway it could only drop once and then disapear.... it should look like that big blue round shit with 350 shield (forgot how is it called). I think that would bring more fun to the game , and defence would become bigger matter....
2. Environment as i've already mentioned, i wish there would be caves where some units could hide, also trees, oh i forgot there are trees already
so thats it i think...
3. I must say that new races could easily break the balance of the game and it would became stupid, and soon, there would be only one or two superior races (when playing online)...
Subraces could work out, it would be basicly the same but each subrace would have small difrences between them, here are some suggestions on terran subraces:
one race could make normal marines, other could make them with machineguns or maybe eith better armor but lets say they would suck on tanks and stuff like that....
4. it would be fun if BC, Carrier, Tank, Goliath etc could do more stuff:
BCs could transport two small units (marines, firebats,medics,ghosts,scv's)
After tank explodes (or if u want more realistic game, when tank has very low HP) marine get out of it or driver with a rifle
..same thing with goliath, vulture, and maybe BC, wraith, valkyre,Sci-vessel and dropship - they could use parachute
)
..Nothing mutch about zergs and protoss on this section
5.All units that explode should make splash damage, but not much, just to add more fun to game
and yeeee, air units could fall ....or explode in the air if attacked hard, and if lets say BC falls on the ground it makes splash like i dunno, hmm... like twice weaker than vulture mine.
Zerg, when zerglings or more possible hydras die, it should make acid splash, but not big, so if there is firebats around it, theu could loose some HP.
Same thing with protoss, when zealot or other energy-based unit dies, energy splashes and other technical units loose some HP.
That would make sence: example, if u kill one dragoon between many other nothing happens because dragoons dont make energy splash, but if lets say zealot fights fith goliath, tank or vulture, it may kill them after dying
6. another great idea, pitty its not mine
watch towers should cost cheap, each race should have them. and it shouldn't see cloaked units, just reveal more space than normal unit or building...
7. finaly, super units, i heard some ideas about flying bunkers, 5 combined dragoons, mutated ultra, etc...
every race should have its super unit. ofcourse it could be killed easyly unless u'd use it wisely. It should be hard to get that unit for every race, but every race should get it in totaly difrent way...
for example, (maybe stupid, but in this topic there can be way more suggestions) zerg ultralisk would need to "eat" 6 marines, 3 zealots or 12 zerglings. and i say eat, not just kill, i dont know but lets say he would get enough some organic sh*t from them and then it would get ability tu mutate into lets say superlisk
))) and than it would become i dont know, just super unit witch is totaly new topic to talk about
Terran maybe would have to "capture some kind of enemies unit with scvs maybe and bring it to comand center and then make super unit
Protoss could mind control some kind of units and when it would have all of them, he could create their super unit, just like those two electricians joins and makes that blue shit (350shield).
Few more very iimportant things about this idea:
It would mostly depend on you, if your enemy could get his super unit or not, because u could not make unit, he needs
or maybe he needs zerg for his super unit and u r terran, but thats not a problem........ because i want to sleep
3am now, im not going to school tomorow
))
ok, if u have any coment about these thoughts, post, but i think they r all prety good ones
...oh and dont forget water idea! ...witch isn't neccesarry
