"Picketts Guard Lake is the small one right at the edge of the basin where it plunges down to the Kern Kaweah. The water source (picketts guard creek?) evidently enters and exits the same side of the lake. It's about 900 feet right above the Kern Kaweah and I've read that the access is to slb SE up the steep slope from around Rockslide lake.. I was wondering about the climb up. Looks like it might be a bit of a test though evidently relatively quite a few people have done it."
Now I know exactly what lake you are referring to. It is the last in a chain of 3 lakes that are connected and sourced by Pickett Guard Creek. It flows into the last lake from roughly the south and empties down a cliff and continues on to the Kern Kaweah River roughly from the east, so they are separated by approximately 90 degrees. I exited the Kaweah Basin via the route you refer to two years ago and the route is considerably different from the info you have. Basically, you drop over the rim that separates the lake from the slope leading roughly north down to the Kern Kaweah River. From there descend contouring westerly around the nose of a ridge that borders the lake on the west and look for a cluster of fairly large pine trees. Be careful not to drop too low, or you will be in for a very steep rough descent to the river. There is a small cairn there which will tell you you have found the start of the route. At least it was there 2 years ago. In any case, at that point, the route will be obvious. From that point on follow the seam in granite slabs WNW and descend to the Kern Kaweah River, which you will reach about 1/2-3/4 mile west of Rockslide Lake. To ascend, reverse the route I have described, but you will have to evaluate the granite slabs you will be ascending very carefully to find the start. Look for occasional trees that, if connected by a line, would delineate a rising traverse. It may take a little time, but is quite doable.
Another route, one I prefer for its aesthetic qualities and micro rout finding problems, is to cross the Kern Kaweah River just above Rockslide Lake. The river divides into 2 channels there. Follow the southern most channel until you come to the end of the large talus slope on the southern bank, then cross and ascend along a wall on your left. Eventually you will come to a rock filled notch which you will climb up through and turn right, following a shallow level gully until you come to Pickett Guard Creek. Follow it on up, without crossing, and take the unnamed east fork of Pickett Guard Creek until you come to a small lake, more like a pond actually, cross the log jam at the outlet, and contour around it on the right and ascend slabs about 700-800' up into the east arm of Kaweah Basin. Camp at the first lake, which has excellent campsites either on flat granite or back in a grove of pine trees. There are excellent views of the Kaweah Peaks Ridge there and it is by far the prettiest part of Kaweah Basin. From there it is easy to cross a low saddle on the ridge that separates the 2 arms of the basin and follow Pickett Guard Creek down along the 3 lakes to the descent route described above. Either way, you are going into my candidate for the most beautiful spot in the Sierra. Whichever way you choose to enter and exit, it will be worth the effort.
Just for the heck of it, I've included a link to a trip report I posted for a trip into the Kaweah Basin in 2009. If you're interested, it will give you an idea of what the place is like and also some narrative of the route finding involved.
"The passes over the Kings Kern divide concern me for the same reasons you mentioned....lots of loose Talus on the hard northern or western sides which I plan to descend and it's always harder to climb down. I've read cautionary tales about Lucy's Milly's and Harrison with the looseness of Lucy's getting special cautionary mention and of course the top of Millys is class 3 and loose."
I think Harrison is by far the better choice of the 3 if you want to exit via East Lake and Junction Meadow(Bubbs Creek version). It is large blocky talus with very little loose rock. There are a couple of awkward moves at the very top, but after that it is basically a talus hop. Once at the bottom of the chute, it is a very pleasant hike down to East Lake. If you prefer a bit more off trail exposure and an exit via the beautiful Sphinx Lakes Basin, Thunder Col is also a good choice, although a bit more sketchy than Harrison. Still, it is safer than either Milly's or Lucy's for a descent, and the route from there is a lot of fun. Just ascending the wide basin beneath Thunder Mtn from the unnamed 3 bay lake to get to Thunder Col is a rare treat. I think this is the lake the guy in your link refers to as Ghost Lake. The creek in the basin, which I call Thunder Basin, has 4 exquisite waterfalls and the scenery is stunning.
"The So-called Little Joe has been mentioned by a couple of sources as the least loose and basically class 2. Maybe you could look at the photos about 4/5th of the way down the page on this link (with nice shots further up of the upper Kern!) and venture your understandably qualified opinion."
From the pictures it does look a whole lot easier than either Mily's or Lucy's. As you said, basically class 2. If I ever decide to head in that direction again, I will definitely check it out. That is unlikely, however, as I found the area north of the Kings Kern Divide to be far too over populated with both people and their inevitable shadows, the black bears. I have since found myself spending more and more time exploring the nooks and crannies along The Great Western Divide, or just hanging out in the Upper Kern Basin. Funny thing about Harrison Pass: I have crossed it from south to north 3 times and never found any snow worth mentioning, but that was back in the late 70's-early 80's. Maybe things have changed since then, or maybe I just got lucky.