Counterbalance? Who's that then?
The only thing likely to happen if PT does get in power, is another coup will ensue.
The elite/PAD faction would allow the government to form and then at some point, if they are threatened again, which is highly likely they would be, they would remove the PT party.
Nothing is going to change as it is. Nothing. Whoever is in power, the other faction will cause a fuss. Thailand is divided and there's no one presently available to resolve this.
All the people involved in power and politics in this country are utterly corrupt. Government, army and police. Trust me on this.