Hi guys, thanks again.
@Airtruth, I chose hill sprints because they'd been advocated on here, and also because it's said that they are less dangerous, due to the minor speed, and the shorter range of motion of the glutes and hamstrings caused by the inclination. Also, I have a steep street close to my house, so they're perfect. But yes, I understand what you mean!
@Farmer, thanks for the good plan! I don't plan to add some more sprints, 6 progressive ones are more than enough, so shortening rests is a good idea! And I particularly like the idea of putting some plyo right before, the jumps or skip are truly a great suggestion. I'm afraid I'll look even stranger to passers by and onlookers from surrounding buildings, but hey-ho... (There's one guy who must take his cigarette break always at the same hour, and that's when I sprint, just below his window. He stays there, elbows planted, cigarette in mouth, and watches me! Would be cool to find him training one day! Motivation is everything!)
With respect to the pull up, thank you again for your enthusiasm. I don't know how common it is in the climbing community: probably more than we think, especially in areas in which the rock is very pocketed. My problem is that when I've done something good, I want it to become the base for future improvements. That's why I keep training many many useless feats. I'm stronger now at 43 than when I was 25 or 30 or 35, and I want to keep improving ideally forever. One of my fingerboarding routines is partially dedicated to one arm, one finger pull ups and I'm still progressing. The aim is to do one with index finger and possibly ring finger, my weakest one.
Sadly I realize that now I'm more of a "trainer" than a climber. I have little time to go on rock and not many projects to try. Hopefully one of them will be climbed tomorrow, though!!!
Thanks for all the suggestions, and please feel free to add more.