This is great stuff Jonathan! The flow of some of your particles is really nice, very fluid like. Great work!
I'm sure you're aware of Pete Draper's great books, all about doing natural elements without plug-ins inside of Max.http://www.xenomorphic.co.uk/publications.htm
If you don't know about yet, you should definitely check out Volumes 2 & 3. (Volume 1 is the same as Volume 2, except Vol 2 has some added things)
I've gone through times when I really tried to do cool liquids and stuff, but I mostly used Glu3d. It's kind of expensive, but I've always only ever used the demo version (FREE). The demo version is fully functional, but puts a small logo in the upper right corner. If it was my own goofing around, I didn't care, but if I was rendering something to be used somewhere, I would render a version with the liquid turned on (with the logo up in the corner), and then I would turn Glu off in the scene and render it again, and with Glu turned off, it wouldn't render the logo. Then I would just patch that corner in with masks inside After Effects afterwards. I still do this, works great. http://3daliens.com/joomla/
Sometimes when using just Pwrapper with Max particles, the logo would render right in the middle of the frame. That's much harder to work around, but again, if it was just a fun test for me, I didn't care. (Pwrapper is the Blobmesh thing that comes with Glu3d, but they also offer it as a stand alone plug-in for turning regular particles into a mesh surface. It's just like Blobmesh, and really fast and with much more control!)
Here's the kinds of tests I used to mess around with.
These all used Glu3dhttp://www.mackdadd.com/CG/water/Glu_water_sean.movhttp://www.mackdadd.com/CG/water/glu_in_cup_01.movhttp://www.mackdadd.com/CG/water/Glu3D_test_04-1.movhttp://www.mackdadd.com/CG/water/table_overturn.mov
These did not, just Max.http://www.mackdadd.com/CG/water/heart_axe.movhttp://www.mackdadd.com/CG/water/rain_Draper.movhttp://www.mackdadd.com/CG/water/boat_wake.movhttp://www.mackdadd.com/CG/water/cloud_flythrough.movhttp://www.mackdadd.com/CG/water/water_shader_01.mov
Looking forward to see what else you keep coming up with!!