Nice thread, Mina.
What do you think were his best scenes? The scenes which required action were definitely Gurmeet's best. He did better when he had to move around in quick motions like the war and battle scenes. He was also good in the God/devotee scenes, like Ahilya Udhaar, Shabari, Guha, Hanuman, etc. The Ram-Sita sweet scenes were also good.
What do you think were his worst scenes? There was room for improvement in those scenes in which he had to act emotional, like in missing Sita, Lakshman, mourning Dashrath, etc. He was okay, but sometimes his expressions seemed forced when he attempted to cry.
How do you think he could have done better as Ramji? Create more of that softness in his expression. Though Gurmeet was good as Ram, and though he had that divinity in his face, he lacked the softness and serenity which we associate with Ramji. If you take a look at paintings of Ramji, there is a certain softness and delicacy in the face of Lord Ram that the painters incorporate, and in the beginning episodes of Ramayan, Gurmeet totally lacked that. He improved later on, especially during the Uttar Kand episodes, but there was still room for improvement. And not only the softness, his dialogue delivery, while good, lacked the gambheer and command of Ramji's tone of voice which is described in the scriptures.
Do you think his dialogue delivery was good? Lols, guess I just answered that in the previous one. Overall his dialogues delivery was good, but like I said, in the scenes which required Ramji to be commanding, like the war scenes, his dialogue delivery was not commanding enough. His tone of voice was not powerful enough when talking to rakshasas like Ravan, Indrajit, etc. Ramji, while being a soft and serene person, was also supposed to be like a leader, and though Guru exhibited that in his acting, he did not in his dialogue delivery.
Do you think he was well chosen for the role? Overall yes. Especially when we take into consideration the other actors of Ramayan, he did rather well. And I also think he is one of the best mytho actors of the new generation, because unlike many mytho actors of today's generation, he was able to portray his role well without it seeming forced.