No, it does not look like redleg. It is normal for their thighs to be a little pink. He does however look bloated. When you feel his sides are they squishy like they are filled with water or harder like a balloon filled with air?

You mentioned that you are using spring water. What type and are you dechlorinating it? Spring water should still be dechlorinated, including any water you use to expand substrate. If you are not dechlorinating then the most likely answer is that the frog is Toxing Out. This accounts for the bloating, listlessness, lack of appetite, and twitching.

Try to get your temperatures up to 76-79 at night and 80-83 during the day and humidity around 80%. You can cover 2/3 of the top of the enclosure with plastic wrap or similar to help maintain heat and humidity. You can also get a UTH and place it on the side of the tank. Those temps will also aid in digestion.

Try nightcrawlers as a staple diet. Crickets are not that nutritious and only have vitamins if you are gutloading them. Either way you will need a vitamin supplement and calcium with D3.