The reason why not, IMO, is by and large that it's a cult that relies on control for retention of membership. My thoughts:
Make the taking of blood transfusion a conscience matter since the Bible forbids just the eating of blood.
The blood policy actually has an enormously useful function for the cult. They've ritualized signing away your life in service to the cult. This is a huge hindrance to thinking clearly about the cult - if you have doubts, why would you risk your life in that way? This is the sort of cognitive dissonance that motivates people to quell their doubts and react with strong certainty that the cult is true. In my case this effect was so strong that even after I'd decided beyond a shadow of a doubt that I had been raised in a cult, it still took me a week or two to actually throw away my blood card.
Have youth programs for the congregations like basketball teams, baseball teams, etc.
It seems that they're moving towards in this direction (with the caleb and sofia stuff, etc), but I'd say that there's a couple problems that keep them from fully doing this. If they have programs specific to children, many places require that those administering it go through background checks or become licensed somehow, and that is likely viewed by the leadership as an unwanted intrusion at best, and at works a big risk of revealing to the R/F of certain congregations that they have pedophiles in their midst when someone gets rejected on the basis of a background check or something similar.
Still not allow the celebration of Christmas and Easter because of the pagan origins, but allow birthdays, mother and father day celebrations. The Cart People currently love baby showers to celebrate the birth of a baby but then they can't celebrate the birth date of the same baby one year later.
The forbidding of holidays/birthdays/thanksgiving/etc also functions as a means to isolate members from society at large. It reinforces the us/them dichotomy, which is critical for retention of members because it makes leaving too scary to even consider.
Only have the best speakers give the talks on Sundays. Too many monotone, just read the outline speakers now.
They don't have enough skilled speakers. They've historically tried to improve speaking skills of the R/F and have been increasing video usage lately as a way of addressing this, though.
Drop the members giving talks during the CLAM meetings.
Personal testimonials and forcing people to prepare and participate goes a long way to increasing the investment people feel in the cult. The more invested someone has been in the past, the less likely it is that they'll allow themselves to consider the idea that it may have been a bad investment.
Allow the JDubs to count time to visit the sick, help the elderly with chores, to visit members in nursing homes.
I can somewhat see this. However, I think the ministry is pushed because it reinforces the us/them dichotomy. There's never a time when a JW feels more separate from society than when they're walking up and down a street on saturday in formal clothes. As with birthdays, etc, this helps to make the act of leaving and going into an unfriendly/unfamiliar world unthinkable.
Not have meetings for service on Saturday mornings. We all need some time on the weekend to chill or just sleep in with no FOG (fear, obligation, guilt)
All cults keep people as busy as possible. Idle time allows people to think things over. See also previous comments about investment. There's also a need for social pressure to get people to go out on saturday - see above about ministry reinforcing the us/them dichotomy.
Only shun those who are disfellowshipped if they are known to be immoral or if they openly engage in opposition to the Borg.
This would cede a huge power that the cult has - by maintaining the mystery around why someone is DFed and announcing it the same way every time (and openly saying that most of the time it's unrepentant sexual immorality) they make it possible to boot anyone for any reason if they threaten the cult's interests. Also, if they stop shunning apostates, the cult would practically evaporate in the span of a few years.
Allow those who just want to stop being a JDub to just walk away and be treated as if they never were a Trolley Guard.
Drop the 1914 doctrine as nulite and stop talking about the end being just around the corner.
It seems like they're working on it, they just don't want to do it too suddenly.
Encourage going college since in the future the graduates will have higher paying jobs for more contributions.
A smaller number (because college increases the odds of people leaving, and one person leaving increases the odds of other people leaving) of more prosperous members doesn't seem to interest them. They also make a fair amount of money off people donating their time and efforts, which would likely dry up if JWs start valuing their time more (which they would if they get paid more). This is also a long-term strategy and it seems that the cult plans more for the short-term (as is the natural result of believing armageddon is imminent) and it also seems that they're in a bit of a short-term crunch for money. Encouraging kids to go to college would almost certainly result in a short-term drop in contributions due to the cost of schooling.
Stop the nonsense of 99.9% of the world's population being destroyed and only the Cart People walking thru the smoke and rubble into a paradise.
Fear is a powerful motivator. Without the fear of being murdered by the isralite god of war, many would be less wary about exploring any doubts about the doctrine that they might have.