John, three weeks ago, I called the same rangers regarding a hike to Half Dome, and got much the same tone. I was told at least three times by my ranger that she did not "recommend hiking Half Dome at this time." We went anyway, and had a grand time. Granted, the snow on the sub-dome was steep, and several people opted to turn back at that point. But it was not difficult, no ice axe or crampons were necessary.
The Yosemite telephone rangers speak to the "lowest common denominator" people, so warn everyone to stay away. They would get into hot water if they spoke positively, and then someone got hurt because "they weren't warned".
Years ago on a Memorial Weekend, I took a group down to Glen Aulin where we camped, and next day went down to view Waterwheel Falls. Pretty spectacular with all the melt! I recall we tried to shortcut cross-country from a point west of Tuolumne Meadows. It was a bad bushwhack through thick forest, with mostly snow. We took the trail out. I am not sure how much snow now covers the trail in that area, but I can assure you, walking over snow in June is not difficult. you would likely find lots of dry trail in between snow patches. Down by Glen Aulin, the river might be overflowing so the area could be a swampy mess. But then again, it might not!
My biggest point is, don't be afraid of hiking over snow-covered areas. It is not difficult.
As for stream crossings: With most streams, you can usually hike up or down stream a distance and find a fallen tree to use as a bridge.
