Not to worry.... 2.5" looks about right at the chine ends. The distance between the chine and keel at cross section 1 is
about 2", ( check your offsets for this) and the separation of keel / chine gets greater as you approach the bow. Same
for the stern. Look at the side view drawing to see this.
The Sea Tour 15 pics you are using for comparison are from an older version of the design, and it had less chine flare, so it's chines are located
closer to the keel than your Sea Tour 17R chines.
The bow bend / slope is up to you and will be effected by the location of the gunwale and chine ends. Look at the Sea Ranger instructions
for the approximate bend location relative to the chines. If you want more slope / longer bow you can make the gunwales longer,
or the chines shorter. As long as each can be pinched together without excess force, you will be ok. As you have mentioned, you could start the
bend further aft to lower the chines relative to the keel. A longer sloping bow is fine. Check using a stright edge to see if it clears the front edge
of the chines when placed between the keel and gunwales as seen from the front. It should be ok.
I recommend that you bend a separate section of tubing to create the bow vs using the keel tube as shown. Once you have the bend started,
you can then trial fit it parallel to the keel before continuing to bend a few more times until it fits correctly. Too little each time is better than too much.
If you mess up by overbending the stems, just start again with a new tube. You will soon get a feel for what works and what doesn't.
At the stern, a steeper bend looks good.
It may take a series of small bends to get it right, so work slowly, and be sure to mark the exact tube location in the bender so that when
you return the tube to the bender after a trial fit, it will line up as before...otherwise, it could easily get out of alignment and you end up with
a strange looking bend.
Sometimes it's easier to slide your chine and gunwale front inserts around a bit to make them match the bend, rather than the other way around.
This is more are than science

Next determine the keel cutoff point, and then cut both tubes and rivet in the first keel insert.
Regards, Tom