I share your challenges with long draw length.
Also, I tend to feel like there are two camps of bow performance, assuming good choice of bow style for the wood selected. First there are bows crafted for absolute speed. Second there are bows crafted for absolute durability. Every bow lies somewhere between these two camps with one parameter coming at the cost of the other.
If I am looking to make a bow that will be very durable at 30" draw, I tend to aim for a 71" ntn length. Can you get away with shorter? Of course you can. Can you make a super durable bow for that draw length that is shorter? Of course you can.
That brings me to the third factor. That is quality of tiller, which comes down to your skill. The higher your skill, the closer you can push to the speed performance side of things without compromising durability. If you are still new to the tillering process and tend to get some unevenness in your tillering, you will have to compensate for it by leaning towards the durability side or your bows will be quite short lived.
As has been said, your skills will improve and in doing so, allow you to increase speed performance by doing things like using shorter, lighter limbs, etc.
On another note, from my experiences, rounding the edges after making adjustments and putting it back on the tree works well for preventing lifting and splits. Also, slow is your friend. Take your time. Your eyes and hands can get tired after going round after round with your bow during tillering and it is easy to just rush a step or not see a hinge after working and staring at it for a while. That usually ends with your bow being fire wood. I have had some bows where the only thing I have done during an evening of working was sand off a couple of rough edges and then call it quits because I knew my eyes were letting me down on assessing my tillering progress.
In the meantime, learn from this one, and as has been mentioned, try a shorter draw length on it. If you really do draw 30", perhaps mark an arrow at a 28" draw so you have a visual marker when shooting. It will help prevent over draw until you define a shorter draw technique. I change my anchor from the tip of my thumb at the corner of my mouth to the largest knuckle of my thumb at the corner of my mouth. It works pretty well for me (may not work for everyone).
Good luck.
