Baseball & Tradition

I heard on the Dodgers v Red Sox broadcast tonight on ESPN, that there was a minor League in the MLB system - the Atlantic League maybe -  that is experimenting this year with a big controversial rule change . The change is to facilitate scoring to break a stalemate in the late extra innings . We all remember with glee, the intensely long World Series game in 2018 that Max Muncy won with a Home Run in the 18th ? Well, if that were a regular Season game it would have been terribly long and boring. Only because it was a Dodgers / Red Sox World Series did anyone still care after 14-15 Innings of a tied baseball game. 

Well, in the interest of shorter games and less marathon games anyway, the proposed rule change goes like this :

 Beginning in the top of Inning 12, and any inning thereafter, each team starts the Inning with men on first and second and no outs .  They are gifted two FREE runners, (one in scoring position) , at the beginning each half-Inning. In the Home half of the Inning, the Home Team also gets to start with two runners on. The rest of the game is then played as usual .
 
Putting aside any aversion to major rule changes in Major League Baseball, (like the Designated Hitter rule used only in the AL) , my first questions are these:

Are the two base-runners that start each Inning the same next two batters who would have come up in that Inning naturally?  Or can the Manager select Designated Runners to occupy the bases without having to alter his lineup; or perhaps having to skip his two best hitters in a tie ballgame?

Can the Manager use any players to occupy first and second base each Inning , or will he have the freedom to draw runners from his pitching staff ? What about using players that were pulled from the game earlier and now become Designated Runners?  Why can't they also be used as the FREE runners on base and then have to exit the game after running, or scoring ? 

Next question is: Do those runners get credited for a base on balls, an AtBat, or what?  If they score are they credited with a Run Scored in the record books? If they get picked off are they then considered "caught stealing ?"

If the Game still drags on another few Innings, can those same runners take their bases again in the 13th, 14th , etc.; or do the Managers have to keep skipping and passing hitters in the line-up ready to bat in a crucial situation? 

And what about the pitchers? If either of the FREE runners score, are they considered earned runs when they score? Which pitcher gets charged for the Run scored? The pitcher on the mound or the pitcher that preceeded him ?  Are they considered unearned runs? And what about a "Save?"
 Do the two FREE runners on base automatically put the pitcher in a "Save" situation ?

These are only a few of the questions that come to mind. If I think on it longer, there will be more.