Chronic unbalance between NOD & GDI

Nod only has the advantage late game. GDI has it in early game. You are correct however because Nod players often abuse/use the Cobra's shield. The shield grants it another 100% life without the need for repair time, so if the cobra goes into a fight without losing its shields, then its a major advantage. GDI doesn't even have the closest thing to a shield. Maybe if some of the research upgrades for GDI were replaced with like 50% repair time discount or a makeshift shield, it would be a game changer. Instead of trying to correct the balance, I would propose being able to research the opposing bases and/or mixed bases to remedy this issue. It would also resolve issues regarding multi-accounting if a player wants to play both GDI and Nod. I could imagine seeing GDI Orcas and Nod Cobras flying side-by-side in the same offensive strike. Such a combo would annihilate everything but the structures. Flak should however be baited by cobras.

I started as NOD but not happy with it. Is it possible to change NOD to GDI ? Thanks in advance.

It is not possible, nor has it ever been possible, to switch factions from NOD to GDI or GDI to NOD

On Tib26, Top 100 players are mixed. Seems to be balanced. I can not show the rest of top 100, but that is also mixed...

Some players enjoy the challenge the GDI presents early in the game in order to gain mid-game, some go for NOD for the various strengths it has, especially in the early game.