I'm sure you can learn to counter that in time, takes a while for the fingers to move instinctively.

Probably a couple reasons for your problem with the sim but first an explanation geared towards the real world.

When hovering a real heli with a tail driven by the main engine (via torque tube or belt) you should notice the heli want to climb or descend depending on the direction you rotate the nose. Reason for that is when you give a rudder command, one direction increases pitch and loads the tail up thus sucking more power and rotor rpm from the main rotor. When you give a command to go in the other direction, you are rotating with the natural gyroscopic forces and basically taking some drag off of the rotor. So, rudder command in one direction gives you a bit of free rpm while the other direction will use some of that power to force the rotation against the natural rotation.

Today's computer radios can easily compensate for this by programming a mix to increase/decrease throttle by a few percent when rudder commands that would normally sap/give power from/to the head are given. This minimizes any climbing or descending tendencies.

This shouldn't be that much of a problem in real life, you can notice it but I fly without any mix to combat it without any real problems. As far as your sim goes, you might be able to tweak and adjust it so it isn't as bad. In this hobby, I suppose you get what you pay for; if your sim works at all and it was free I guess you can't expect much more.

I use phoenix for my sim time and have enjoyed ever since opening the box.