Alternate Spinner Forms: Its because CtB has more spinner overlay and when osu! handle it it appears randomly, well at least it stays the same, but sometimes it ruins the patterns since it needs a testplay to place the objects after/before it at the best possible place. And its annoying if the map has many spinners. So it should be an overlay? option just like combo colors have to be able to choose which one do you want to use.
End of the Screen: This is optional, but since maybe with this the grid will be a bit useless it will be hard to know where the screen ends and offscreen fruits are just crazy. o.o So it should be something which reminds the mapper about where are him/her at.
Timing Points: I'm not sure if this really needs describeing since they should be the same as above on the timeline but this way you just only need to watch in the middle to know where will you place that note on the timeline. And also you can see everything in realtime w/o testing it (well it will still required).
Scrollbar: This is really an optional stuff since maybe it isn't really necessary, but it will be good to see where are you at w/o looking at the bottom which is I think its kinda disturbing. And other option is to place the bottom line (I dunno it's name) at the right side of the grid. Well this whole option is mainly works only for 16:9 but maybe it can be added for 4:3 too.