I know this is a very old post but I'll reply anyway.  My hair is relaxed and fairly strong (I say fairly, because my hair type is 4a, which is naturally very dry and naturally fragile).  When I didn't have a relaxer, wash days litterally took forever like 12 hours to wash, condition, dry, detangle and press.  I reluctantly made the decision to get a relaxer because I just couldn't take it anymore. 

My relaxer trick is to keep the relaxer on only long enough to "relax" your curl pattern just to where your hair doesn't draw up when wet.  Everyones hair is different, so you'll need to see when this time is for you.  My hair is not bone straight at all.  It still looks and feels natural but, it is now much more manageable.
I also deep condition under a hood dryer almost every time I wash my hair.  Conditioning is very important.

As long as you don't use heat on your hair regularly, or use color, you can still have strong hair if you relax this way.  If you do decide to use heat, don't do it everyday. I read that 3 times a week, with low to med heat is the absolute max.  Molecular rollers are good to use too.