Bandwidth management, RB450G, simple network map. Need help.

I’m trying to do some bandwith management for my home network. I’ve followed these 2 examples(+some adjustments, because I have 2 separate networks behind the router), but I failed miserably.
http://www.mikrotik.com/testdocs/ros/3.0/qos/queue_content.php#.6.3
http://mum.mikrotik.com/presentations/CZ09/QoS_Megis.pdf

My network setup looks like this:
network_setup.png
I want to add that PC1 sometimes runs a few VMs in bridged mode.

The ISP connection has 2mbps down/1mbps up external, and 100mbps down/20mbps up metropolitan, but these speeds aren’t steady.

What do I need?

I need to dynamically allocate bandwidth for PC2. Whenever it needs bandwith, it should be able to take up to 40% of the total bandwith.
I also need to be able to limit upload speeds on specific ports from 10.223.44.2.

How should I proceed?