How many Objects can you replace with special objects in a game? Can I replace all my objects with special objects?

no i think its like one for every 300 pts.

The blue ones, (the immobile ones) are 1 for every 300 points.

Immobile (Blue) are one per 300 points and can be switched out for light or heavy. the rest can be switched out at will (dumpster, generator and laser turret, if you're lucky enough to get three heavy objects)

... and the rest can be replaced with whatever object matches up with the appropriate light/heavy bordered objects you pulled out of the pile.

Just remember they are considered unique (no multiple Laser Turrets) and special objects must be placed more than four squares away from the starting areas.

I recommend reading the section on object in the DR rule book. Covers all this and more.

I have some questions:

#1-when using the Broken Drone from DR-does the object get destroyed when used in a ranged(thrown) or cc attack?

#2-when using the teleport pad:
a)is a character allowed to move up to it, and then use it the same turn?
b)Can running shot or charge be performed through it to attack another character?
c)can a character be tk'd through it?

Yes, only the dumpster and generator are not destroyed when used in an attack. However, if you use the drone's special ability (making that 4 range, 1 damage attack) that does not destroy the drone.

Using the teleport pad is a power action. You may not give a character more than one non-free action per turn. So unless the character was TK'd up to the pad, no.

No, see above.

Through it? No. They may be TK'd up to the pad, and then the character could activate the pad as I described above.

1 yes

2 no
no
and no

Can the Aerial baffler be destroyed if you have 3 damage?

Yep, same as other objects.

I have a question: can a separate character take the power action to use the Teleport Pad to move a different character with it (who would then be free to take an action afterward)?

Since TP says "give the character a power action and move it up to 6 squares", you couldn't give a character a power action to move a different character with TP.