Irish Based FF considering switching from Skyteam to BA

HI,

I am a Platinum medallion with Delta/AF flying from Dublin. Make about 3 long haul multi-leg trips a year to the US with Delta and 3 long haul flights a year to Asia with Air France. All in low cost business class with AF and upgrade-able high economy fares with Delta. Also fly a lot around Europe with Ryanair and Aer Lingus.

With the possibility of Aer Lingus joining IAG and the serious reduction in benefits and earnings with Delta I am now considering switching from January 2016, Some questions:

(i) Roughly what Tier level would I attain with above flights?
(ii) Do BA do Status Matching?
(ii) Roughly what would I earn in Avois points?
(iV) Is this a good move for me?

With Delta reducing my mileage earning by 18% and also taking away my 4 upgrade certs. Having to pay for the certs in miles means I earn roughly what I spend in miles

Thanks for replies in advance