Vintage Postcard Mystery - Help me crack the Case!

[4reals]

Not long ago I obtained some vintage postcards sold to me by a gentleman who's father passed away. They were in his father's sportscard collection and he knew nothing about the back story of how he obtained them.
There are 1 football and 6 baseball themed postcards. They are somewhat risque for the time depicting flirtatious acts and were wittingly entitled with a framed caption.
The copyright line is found on the bottom of the caption frame on the front of the postcard. It reads: copyright 1910 by the colonial Art Pub. Co., B'klyn, N.Y. Published by F.G. Henry & Co. Inc. N.Y.
These were obviously part of a set, but I'm not sure how many the set consisted of? I've seen at least two more on ebay of the same style entitled "A Highball" and "Breaking her Contract" so I know there are at least 8 different baseball ones. Any additional background or info on this set is appreciated.

What I'm really interested in, however, is on the OTHER side. All of these postcards have been written, addressed, and postmarked. All are written by the same person to the same person over the course of 5 months. I've deciphered the handwriting and have typed out each letter below its image. Some of the words I could not make out - they are in red.

What I am looking to accomplish:

1) decipher the remaining words
2) identify who the sender and recipient were
3) identify and locate relatives of the sender and recipient
4) contact the relatives of the sender or recipient and gift them with items from their family history

I have not had any experience with genealogy and quite frankly am too intimidated to accomplish such a task by myself. I thought it might be interesting to make it a group project and follow this rabbit down the trail wherever it may lead. Considering the subject matter on the front of the postcards is baseball related and quite a few baseball references are made throoughout the letters, I figured this would be a good place to do it. Whether you are able to help or just want to come back from time to time to see if any progress has been made I appreciate your time and interest.

Also, let me request, if you do quote a response on this thread that contains an image, please remove the image from your quote to minimize the amount of scrolling we have to do, thanks!