Nearly all of that, damn that's a nice list.
The pricing changes make sense, I hate them on my business side, but they do make sense on their side. Online marketplaces and such tend to have painful fees.
Items: Anything older than 10 years should not be on MP, they can still exist in inventory but reduce the spread of it. Let the new take over the ancient and clunky. Of course anyone active can re-post them.
Accounts: Apparently I had account older than 16 years that I never used. Send email that all unused old accounts are getting deleted, free up names so you can later use them again, ease your database.
Land-setup fees: These are still too damn high. Switch to cloud hosting already and reduce these down to month's rent at least, preferably down to half of it. I am guessing here that the main issue is possibility of too many private sims pop up and die right away that would cause too much stress, and it would be better to allocate land that already exists.
Piracy: Have at least one person familiarize and scout the SL market to take out the copybotted items. The baked on mesh will help, but even checking every two days you can find so many items that are obviously copied. Piracy is often due to ease of it, or too high prices, I don't expect it to ever go away but you may certainly take some effort to reduce it when it is plain and obvious.
I bolded a thing, it's not really noticeable. The heck?
Depending on how much effort it is, provide a SL social site inspired by Instagram. Add flickr's groups, sell it as a high quality service for bloggers since it combines best of all. This causes SL to spread less in the social media, but it also creates a very inciting and more interactive population. The new web profiles with spots and all were a good idea, just executed badly.
Take a professional level designer, UX designer, some SL veterans, some Lindens, and make a proper bloody tutorial area and introduction to Second Life. It is abyssal, I would never made it if I didn't have a friend in it already to pull be back in. Also add referrals, or bonuses for people who take new residents under their wing. Why? Because it's immensely complex to anyone not computer-savvy.
Get better marketing, utilize Twitch (after you create a fool-proof way of countering any trolls), encourage your media creators. SL offers you to explore your sexuality, your gender, your personality, your limits, pretty much everything. You can be -whatever you want-! Do you know how many people want that? You still haven't developed a proper approach for acquiring your potential userbase.
Redo your official Viewer, the fact that most people use TPV speaks for itself. Plus, it's a mess from what I recall using it last time, so it should be tied to the new tutorial area. The other path is to add viewer feature bounties, like Coffee said, and use your TPVs to push forward, support them and they will bring you many great things. Just imagine more professionals pushing your viewer forward with some minimal upkeep on your side, it's a good investment.
Provide more script options, while you wanted Sansar to have games in itself, SL already has them. Give people the tools for it, make combat smoother, easier to create. Improve UI scripts. You could run a good RPG on SL if it was easier and/or better.
Set a limit to a complexity a single item can have when worn on a person. Combined with your attachment limit, this should give some sort of an upper cap. Or have the graphic option to reduce most complex items to one LoD lower and save us the sanity without turning people into weird blocks of color, which causes more question and confusion from new players.
Scalable sims: Give options for owners to decide what they want to purchase. More prims? More people? More land? Add options for it, you could approach this like customizing your phone tariff plan.
Also improve your sims as much as you can, some other virtual worlds are making bold statements concerning amount of people in one sim (however they all lack in other aspects so eh).
Improve your Inventory system (tags (can even use MP categories to auto-place some), searching by permission,attachable image), add image previews for Outfits (rezz avatar in a separate space with items, snapshot, seems easy).
Add a client-side supported weather, it adds a ton to immersion but it is too heavy on server side. And immersion is important.
See about allowing more complex animations, as they are quite important for immersion and the feel.
Allow basic animation manipulation tool. How much more interesting would it be to actually wrap arm around someone rather than type '/me wraps their arm around you' while you are clearly not doing that visually.
If you're not going with VR. Can you still utilize their controllers? Moving arms around, later when the technology catches up you can expand on it. But actually dancing or at least trying to seems like fun.
Marketing again, collaborate with some music artist to show off SL to the public eye again.
Tie avatars and all into one account, pretty much parroting what Coffee said, but unite them all under one account. I have so many I need to look up names, then restore password, it's a mess. Sharing inventory items would depend on LL's data on how much do people with alts spend on identical items.
Offer a discount to larger corporations who want to make their presence on SL. Last time it went bad since they don't know what they're doing, but have a person who can 'translate' what they want into SL terms.
In my opinion Sansar has great potential, but it won't reach it until they reduce all loading times massively, allow greater avatar customization, another camera position, and allow some adjustment to how much lighting/shadows an avatar accepts from environment.