I’ve tought that the blocks are 12.5 zCash generated every 2.5 minutes …
How the heck I’ve mined “2.16750000” - what is the knowledge about zCash that am I missing?
Screenshot from src/zcash-cli listtransactions:
Can anyone explain me what it will be to mine on the production after 28th of October? I’m not using any mining pool so I shall be mining a whole block of 12.5 ZEC or 50 ZEC?
Normally block reward is 12.5 ZEC every 2.5mins (so 50 ZEC every 10 mins as per Bitcoin initially).
There is currently a mining slow start and also a founder reward of 20% you can see what the block reward is with the command getblocksubsidy. More details about slow start are here https://z.cash/blog/new-alpha-release-mining-slow-start.html
OK - so after 28 October - what will be the initial block reward on 29Oct 2016? 2.5ZEC (minus block subsidy)?
When the full 12.5 ZEC reward after the 29 Oct will be fully received by miners?
How many ZECs will be mined in first week 
in total with what reward per block?
Btw. just curious, I will read your links as well
First week; circa; 1 coin pr. minute = 10080 coins
circa 29 Nov it will be 12.5 pr. 2,5 minute
Genesis block reward is 0 ZEC, block 20,000 is 12.5 ZEC, blocks in between are linear.
Difficult to know exactly what it'll be on 29 Oct as early blocks will likely be faster due to difficulty but it increases by 0.000625 a block and founders reward is always 20%. If you assume that there will be 576 blocks mined in a day (1440 / 2.5) then you can expect the block reward to increase by ~0.36 ZEC per day.
So just checking the maths 20,000 blocks at 576 blocks a day means mining slow start lasts 34.7 days (it'll likely be quicker due to faster blocks at the start).