1. Is there any limit in Electrum 4.0.9 for a large number of addesses subscripting to the same notifying URL?
What do you mean by notifying the URL? Is that the address that you requested from "receive tab" when clicking a new address?
If it's that what you talking about then you can request many addresses without any limit but take note of the gap limit it will generate new more unused addresses when hit the "gap limit"
You can see all used addresses under the "Addresses tab" just make sure to turn it on/show the addresses tab you can find it under view>show addresses.
2. Is there any way to identifying the address as a receiving address or change address in a wallet? In addition, can I make any limit to the number of change address in Electrum Wallet?
If you follow my guide above just go to the Addresses tab and scroll down you will see receiving address and change addresses.
Here's what it looks like
On the left side under "Type" You will notice which addresses are receiving or change address.