Does experience itself hold any value

[Tenet Nosce]

My understanding is that creator let different parts of itself to interact with one another to explore itself on a more micro level, the purpose is to gain a more refined (dense?) understanding of itself, to know its essence.

Therefore experience is only a tool not the purpose. The value of experience is that all creator is doing is experiencing itself, no understanding can be archived without experience (I guess).

Yes, I believe that is a fairly accurate summary.

1. Does different kind of experience lead to different understanding or merely generate different ways to the same understanding?

Ultimately, identity is the only thing to be understood. All paths lead to the Creator. But there's a ton of other interesting stuff along the way. E

Ra said they are worried when there is little harvest at the end of the second cycle. But Ra also acknowledged that even if earth is destroyed in unclear way, this still bring useful information back to creator.

Where did Ra express a concern over the size of a harvest?

2. Do we always have to learn something from experience, does experiencing just for the sake of experiencing without understanding is not good practice?

We don't "have to" do anything. Often times the understanding comes later. But I'm not sure where your question is coming from. I am left with the impression that you would consider learning as a chore or something that takes too much effort.

Learning from experience is easy. Simply look within.

Therefore indulge in experience without learning is not advisable, and the information from these experience are not really a fair trade for understanding lost.

They do possibly suggest (depending on one's read) that continually unused catalyst may manifest as illness, however ultimately "There is no lack of space/time in which this catalyst may work (46.16)"