Great news. Hope this spirit of co-operation with GW can continue.

So, Hena, what are the least controversial, minimalist changes you need to the Marine lists?? For what it's worth, I would like to see the following changes, possibly presented in order of priority like this:-

Land Raiders
Land Raiders underperform and are overpriced against other races / units to the extent that they are rarely used - yet this is one of the most iconic units in the game
- Land Raider FF improve to 4+
- Land Raider cost reduce to 350
- Land Raider Upgrade reduced to 75
(Note I would change the Land Raider upgrade to 75 points to simplify the army list maths)

Dreadnoughts
Again, one of the most iconic units, Dreadnoughts are rarely if ever used
- Dreadnought Armour improve to 3+
- Upgrade 1-3 Dreadnoughts

Vindicators
These are never used because they are so poor compared with Marine armour, which is itself generally underpowered / overpriced when compared with other races
- Vindicator speed to 25 cm,
- Vindicator weapon to MW4+

Predators
These tanks still underperform badly against other races / units in firepower and armour, so are rarely used
- Predator cost to 275

Terminators
The one Marine formation that is really a bit overpowered, so a price increase to reflect this
- Terminator cost to 350

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Note, I really want all the changes to be included, but IMO the others are perhaps just a little less urgent/more cosmetic.

Unless I have miseed something the only MW that SM can field are landspeeders and allied Warhound Titans.

You have indeed missed something, which is that the demolisher cannon is also used on the leman russ demolisher, and it has been proven by extensive playtesting that it is broken at MW4+.

note that I didn't say it is the wrong decision, merely that it isn't uncontraversial. That's beyond doubt.

Current wisdom is to either improve the vindicator by upping the speed and adding walker or simply to drop the points cost down to 50.

To reinforce what Chroma said and add some additional detail, a method for duplicating the original rulebook's layout which is not ridiculously onerous has been created/discovered.  Given that we're dealing with GW there are, of course, IP issues to consider.  If things go well we may be able to start generating an integrated document soon.  It still won't be quite as easy as copy/paste but it should go smoothly.