I don’t think the every other day program would be helpful to a cah’er with any degree of cah--mild or severe.  My reason would be that it doesn’t mimick the way cortisol is made and therefore I personally feel it would leave you high levels on the first day and extremely low to non existent levels on the following no dose day.  It would be far better to be consistent with your doses, reduce them and spread them out further than twice a day IMO than take hydrocortisone for an adult only twice a day.  Hydrocortisone only has a life of 6-8 hours and then it’s excreted and there will be periods in your day where your lacking or very low on the stuff and then at other times, quite high levels compare to what normal physiological type levels are in folks without CAH.  I mean even if your not working out or exercising, to my mind, after taking hydrocortisone at 6am, at around 3pm, your body must be so low on the stuff, I am thinking that your energy levels even on a normal day without exercise must be zilch.  I’d say take 10mg morning, 5mg at 1pm and then another  2.50mg at 5pm = 17.50 mg daily and not a large dose really.  That to me would be a better combination than the twice a day stuff or the every other day dosing.  If you find your bloated a lot then you need to watch your sugar intake and low glycemic type carbs.  Restrict them to accurate portion sizes throughout the day and stick with clean type carbs such as yams, sweet potatoes, brown rice, wholegrain or steel cut oats etc.  Eat 5-6 times a day instead of 3-4 times a day and keep your carb portions as small as your clenched fist at each sitting.  Drink plenty of water, because if your dehydrated, your body will hang onto it and the water flushes out excess sodium quickly when you do that or dilutes it somewhat so it doesn’t give you that bloated effect as much.     If your feeling sick and have to double up your med’s then drink sugary drinks to keep your blood sugar levels up. 

Alternatively you could switch to dex once a day at a very small dose if hydrocortisone is causing water retention as dex tends not to do that.  It doesn’t have mineralocorticoid properties, whereas hydrocortisone does and to some degree you may get water retention on the latter if the dose is too high at any given time in the day.  Tweak those doses.  I would do that until I felt they were just right.