>>/1799/
> will it feel like they are adding to the shows world or will it feel like they are just taking away?
I would like to answer that question properly and I would be dashing with conclusions too soon. 
It´s a good question though that we will have to answer with the after thoughts. 

> If we get interesting scenarios and lore with a well written arc that touches nicely upon everything I could see it being mind blowing and fun.
> new characters not well developed and it trying to bounce around a cluster of unresolved plot points and every question of the previous seasons 
fortunately enough for you, a new episode has aired this weekend that will chill out us in the meantime and for sure, What Lies Beneath will deliver something else before the finale. 

> I could see Rarity or Apple Jack not getting a solo episode that season. I somepony like Sandbar being left behind as well.
Sandbar is not being forgotten, he´s just an average pony that brings the expected cliches that other species would make about the pony race. He will most likely appear for the comical situations...just like Vincent Tong did in the past with other roles.
About AJ and Rarity, they will have something else to say but the least surprising one to give us will be AJ. The background orange has been the perfect role model since the beginning but certain gossips are predicting a new challenge for AJ in this season...time will prove that statement right or wrong.

> I could see the road ahead being bumpy with what ground work is around right now.
the road may be bumpy but I have mentioned that finale because those characters weren´t in the beginning either and they delivered great moments. It´s not the first time they experiment this and the background....doesn´t need to be that complex as we would imagine.

> I specifically was helping soembody out who has mobility problems on the short term, yeah I know that feel very well with my grandfather and next door neighbor who I hep with tech stuff
oh shit, that´s serious stuff. Alright,understandable and something to dignify. I cannot say much beyond that. 

> man sometimes it is hard to get them to understand what I am doing. can't complain either. 
I have known that feel with my father as well and that´s because the brain get lazier with age and we reject everything that is new or out of the comfort zone for us.
Literally,occupational hazards which cannot be fixed much but overcoming them every day.