First of all, I'm happy to see that you are embracing the new workflow tool. It takes a bit of learning, but once you get the hang of it, it can really make life easier. Or frustrating, when it's not working - I've been there myself!
In your case, the trick for the first issue (script not running) is to connect the table iteration to the configurations, not their names. That is, click the connection icons (colorful squares and circles) on the TableIteration block, and connect the Table to configuration_table, instead of as now configuration_names_table.
On the last issue, I think the problem is that variables in Python cannot start with numbers. Therefore the titles of 6AL, 8AL etc all get translated to "al", instead of being unique for each configuration. Try using AL6, AL8 etc instead.
Finally, for memory, since the variable "configuration" is updated each step in the loop with a new geometry, memory will not accumulate in this specific script.