first thing- you do not want to mash (or really brew, period) in the same vessel you use for fermentation. you will figure it out quickly how much of a pain it will be to clean everything between batches.
2- if you have a pump already, you might as well circulate the wort for the entire mash. this eliminates stirring for the most part, and will create a grain bed filter so you will have crystal clear wort for boiling. when you have a HERMS/RIMS system, you will be circulating the whole time anyway to maintain temperature.
3- you want an open boil kettle. you are trying to evaporate water volume, and should encourage it instead of inhibiting it. while its true big commercial breweries usually dont have open kettles, but they also blow quite a bit of air into the kettles and out thru ductwork. relying on evaporation pressure alone to push air out is not going to be sufficient. you want good circulation of fresh air.
you also will need to be adding hop additions, stirring, sampling, wathcing for hot break, etc so a lid is going to get in the way. not least to mention- a piece of hops or hot break clogging the pressure release tube or safety valve and turning a boil kettle into a boiling grenade...
if you havnt had much hands on experience with the whole general brewing process, i would suggest doing it a few times before trying to nail down an automated system setup. i know that when i first started, before i even brewed, i thought for a long time about and planned how i wanted my setup. then once i had all the parts and i started actually using it, i began to figure out how to do things way more efficiently then i had first imagined, and the system changed considerably. yours still seems more complicated then necessary.