PPPoE and PPtP routing

Hello everyone,
in various routerboard that are behind the AP, I have this configuration:

PPPoE server with pool1
PPTP server with pool1 (remote VPN)

Now, if my client is connected, so its PPPoE client is authenticated, he also got an IP from pool1 eg 172.20.90.200; remotely connecting to the VPN, PPTP client gets an IP address from pool1, for example 172.20.90.201.
At this point he can, if the doors of its routers are configured correctly, see DVR, cameras, servers, etc. who are behind the router, without using public ip.
First question: do you think can lead to some problems this configuration? For me using it, it seems not, and you save a lot of IP.
Second question, and is the most important: how can you assign a static IP PPPoE client?
Let me explain, if in the profile of the PPPoE server I configured as the Remote Address pool1, how do I assign an IP statically to a particular client? Is there any way to have PPPoE client both static and dynamic?

Thanks

Just type the IP address into that field in stead of a pool name.
so type, for instance, 192.168.45.167

If you want to tie a static route to the account (route a LAN of addresses through the tunnel) then this goes in routes:
so for the customer 192.168.45.167, the route could be “10.12.100.0/24 0.0.0.0 1”