Need to collect MAC addresses and then reserve the IP addresses. Input a schedule and time frame on when they are allow to connect and set up a policy. One thing about Utorrent and such, the port numbers are not static an change randomly so setting up any port rules might work however you'd have to set up static port numbers I believe in the client software and the set up port rules to deny them on the router. However this doesn't prevent the user from going in and changing the ports. Are they wired or wireless when connected to the router? If wireless then you can just set up a wireless schedule to shut off at a certain time.
One thing I would do if your dads name is on the acct, either have them get there own acct or have someone take over ownership if there willing.
The DIR-605L is a could router and I believe has of the same features as the 655. The 605L doesn't have guest zone though. The new L series routers are all could routers.
If your curious about them I would contact DLink sales and ask for detailed information.