Hey man I have a bloombox too. I had the same problem with slimy roots but the guys at Advanced Nutrients said it was just the carboload and that it gets foamy when aerated. I cut back on the carboload about 1/3 and it does foam sometimes but not much. I don't think the foam is the cause of most of the problems I've encountered.
Sometimes I run strains that get rust spots or yellowing/browning edges too even though the exact same nutrient program worked wonders for the previous strain. Unless you sit there all day monitoring the PH and PPM levels and know the plant already, it will take time to dial in a strain. Sometimes you get lucky though like the time I pulled 5.5oz off of one Nirvana Skunk Special in the bloombox flower chamber even though it had rust spots and burned leaf edges, it still pulled through fine.
You might be over-babying your plants a little like I did when I ran my first two or three batches in the bloombox. I had more problems when I watched them intently every day than I do checking on them for 1 minute per day. I tried to solve every last brown spot, every last leaf crinkle and guess what...... that's impossible unless you have years of experience that I sure don't have.
Hope the bloombox is treating you good man. One thing to try for the high water temps is freezing a few water bottles. Then you just put one or two of the bottles in the reseviour each morning and remove them at night to re-freeze. I kept a stock of em on hand when my room temperature used to get 80+. Now I have it at 72