Regarding #2, I don't ever recall Google giving current month's search volume data in the old keyword tool. As far as I know, they showed a rolling 12-month average which was usually 1-2 months behind. If you wanted numbers at the monthly level, then you would have to export your results to get the monthly breakdown. Even then, the export didn't include the current month's data. For example, if I exported some keyword data in July it would only show me up to May.
Also, the reason I found search volume data differing between old KW tool and new KW planner is because Google now lumps all device types into one number. Previously, they defaulted to Desktop and Laptop only, so you'd have to change your filters to get Mobile. Now they lump Desktop, Laptop, and Mobile into one number which accounts for the higher search volumes in the current tool.
Also, the reason I found search volume data differing between old KW tool and new KW planner is because Google now lumps all device types into one number. Previously, they defaulted to Desktop and Laptop only, so you'd have to change your filters to get Mobile. Now they lump Desktop, Laptop, and Mobile into one number which accounts for the higher search volumes in the current tool.