Lets see if we can make some headway here.
Adding the water cooling won't weld differently, it will just keep your torch from a complete meltdown. Water cooled torches cannot handle very much current nor for very long. A water cooled torch without the water is NOT equal to a gas cooled setup, perhaps one quarter of its water cooled rating. Even then I would rather use a true gas-cooled setup rather than ever do any actual welding with a dry water cooled torch.
On to your aluminum problems. These first are basic, but we have to eliminate fundamental things to get a known baseline condition. It appears that your alum plate can be welded, but not all aluminum alloys do so readily. If you could get a known piece of 6061, or verify that this is, that would be good. Once we figure out your problem, it should weld through anything on this plate, It looks clean enough to get a proper weld laid down. Make a habit of a final wipe with acetone before you weld.
Verify Torch in NEG terminal, work clamp in POS.
There are sporadic signs of cathode etching, so somehow we are getting some Electrode Positive cleaning action. You need to verify it's going into AC mode. Toggle from DC - smooth & quiet, to AC - 100hz or so, it'll buzz at a nice medium frequency audible tone. Make sure AC is operational, btw, do not use pulse for these tests, please.
Gas flow can cause what is shown, so we need to test gas flow from the regulator to the back of the machine, to the open end of the assembled torch cup. Pull gas hose from back of machine and test regulator for proper operation. With an open hose dial in flow rates up to perhaps 15 LPM and back down to off. That proves the hose and regulator. Next we need to re-install hose and test the flow through the machine's gas solenoid. Disassemble the torch, remove cap and collet body, use a bare torch for this. Then in Lift Start (so you are not dealing with the HiFreq. mode), hit the pedal and see if you get a good flow at various settings all the way to the bare torch end.
Test for leaks through the entire system by blocking off both sides of the bare torch, hit the pedal and see if you have any flow, you should not.
If all good so far, build the torch back up, and be careful that the collet body gas holes are not blocked by the cup. This can happen if the insulator keeps the cup out a ways on the collet body threads. Use a #6 cup, and with the torch reassembled, with 1/4" stickout, verify a setting of 8-9 LPM on the flowmeter, and listen and feel for good flow at the open cup.
I would be interested in knowing if your successful steel tigging you mentioned had any red smoky areas or if it was pristine when complete.
If all good so far then make the following machine settings: Use pedal, AC mode, 2T, Pre-Flow 0.5 sec, Post-Flow 5.0 sec, Up/Down slope Off, 200 Amps, 100Hz Freq., 30%EP balance, freshly sharpened tungsten, 1/4" stickout, #6 cup, good ground connection, HF Start, 4043 filler.
If the tungsten burns into a loose dribbling molten ball, there is something wrong with the balance, it should stay sharp and just soften at the tip. If it balls badly, re-grind and try setting balance the other way, this would indicate a machine issue, as Everlast machines reference % of Electrode Positive.
If you can sustain an arc on this aluminum, with an arc gap of about 1/16", you should be getting good cathodic cleaning, a light foggy area around the puddle, and a shiny puddle. Make sure there are no breezes from fans or other to blow away the shielding gas. The fans on the machines ARE enough to ruin your shielded environment if at just the wrong location.
If you dip the tungsten even the slightest, stop and re-grind it, there can be no aluminum stuck on it.
If you complete each step in order, and still have issues, I'd look at the gas, try a known good tank, even if you have to borrow one.
Hope we can get you going soon, report back your findings when you get a chance.
Edit: This is funny, while I'm writing this long post, Rambozo and srp make posts covering similar salient points, that happened last time, too! Oh well, we're just trying to help a guy out, good advice men!