Moving parts in 3D

I posted a previous question about using Solidworks to construct a sculpture (here): from those answers I've managed to import two of the parts of the proposed sculpture but have a few questions that'll hopefully take me to the next stage. Please bear in mind, I'm an absolute beginner - I'm not looking to learn how to construct parts and assemblies from scratch, just enough of SW to achieve my sculpture model: this is my own learning mode, by doing specific tasks.

I created the parts using dxf files exported from Illustrator to build the 2D sketch. I extruded each by 3mm (the actual size of the lasercut wheels), and applied a high gloss black plastic appearance. I created an assembly of two of these wheels:

Q1: I'm having trouble moving the parts and the model. I want to be able to move both in any and all directions to play around with placement. If I right-click on a part and select 'Move with triad', I can move in different directions but it seems more restricted than typical 3D viewing apps. Is there such a feature? And can I do the same with the model as a whole - I'm sure I did manage to achieve this at one point but had no idea how I got there and promptly lost the ability next time I changed something.

Q2: Moving the parts around is fun and I do want to be able to overlap them while playing around, but was wondering if there was a setting that would stop me moving one part through the middle of another so it emulated the real-life wheels that I've had cut.

BTW, if questions like this belong in another forum, please do say so - I just thought this was the best place to start.

TIA,

Tony.

SolidworksGeneral