Why narrow the pool i havent had any problema with ip setting.
Because you need to statically assign an IP address to the Dlink router and you do not want that IP in the pool. It may cause an IP conflict later. Networking 101.
I dont want to connect the AP on the modem cause they are 100mbit as i said previously.
Correct. You can connect it to the DLink router (LAN port).
So for example lets say i do that and connect dlink on lan1 of modem and asus on lan2. I am on ground floor connect on dlink and want something from a device on the basement that is connect on asus. If it is a large file transfer then i will get monstrous 100mbit speeda cause dlink will go throuhh modem and from modem to ap2 to get me that file.
What i am asking is modem-Ap1-Ap2 connection
Also correct.
So what exactly is the problem? You said clients connected to the ASUS cannot access the Internet?
Is there DHCP enabled on the ASUS AP? If yes then disable.
If you have a computer connected to the ASUS, try to ping the Internet. Ping 4.2.2.2. If you get replies, you are on the Internet. Ping Yahoo.com. If that fails it is a DNS issue on your clients.
Also when you say you cannot get internet on the DLink router, are you referring to the Internet settings in the web UI on the DLink router? If yes then it will not have any settings there since that is for the WAN port. You are turning the router into a switch/AP so there will not be any settings there.