this is some stuff that I would change:
I would periodize it better. there are numerous ways you can periodize a program. check out the stickies in the training section to find something that you would think suits you, there are many MANY different ways you can tweak a workout so that you are always progressing.
you have absolutely no pulling motions. you said you wanted to add in pullups which are great, but you need some more type of pulling i.e. DB rows, BB rows, Supine rows...etc.
as for the situps and pushups I'd scratch doing that completely and add some core work i.e. planks, side planks, dragon flags, cable chops (if you have a cable machine to work with) on your workout day.
that is just something that I would change, don't know what others will say, but you'll get some good advice around here.