The way I see it there was only one (major) screw up by max this season (Hungary) the other collision to my eyes are more on the conto of the other driver involved but OK.
The clutch did not engage and he could hardly get underway from the start position, then was rammed by Kvyat (he only was there because of the clutch) and after that you could hear the clutch slipping several times, surely not an anti stall issue. He had to retire the car lap 1 (didn't finish the lap). Max himselve post race said that even if he would have been able to get going he would have had to retire at the first pit stop as well. I am counting this one as a mech failure.
I surely hope RBR will try to sign Ricciardo longer as well. Nr1 or 2 is a bit of a non-issue if both drivers are more or less on the same level. You are totally right in saying he is much more mature, he knows when to make a joke and how to bring it and often helps Max out (who tends to be somewhat overly serious) and for sure a big part of the good atmosphere can be written on his account. Also on track Ricciardo is very mature. He tends to stay out of fights / risks that Max does take. For example Japan first corner, Ricciardo gives the room that others (Max falls victim of this sometimes still) simply refuse to. Sometimes you have to fight but you also must know when to recede. It is a hard choice.
Also, Ricci is a good deal faster then either Bottas or Kimi to my eye so if he goes to either team it will be a tough nut fro Max to crack, so for that reason alone I'd rather see him in the RBR just as max, equal cars! Also I think RBR (if they can finally start the season on the front foot in 2018) might have a crack at the WDC/WCC.