Better Inserters

[SnailsAttack]

First of all, all inserters should have 2 slots for filtered items, whereas the filter inserter should have 10.

The long-handed inserter should have a button on the inside that allows you to change how far it reaches and how far it moves items. Those 2 values would range from 1 to 3.

Swiveling Inserter

The swiveling inserter is a new inserter that can pick up items and move them 90 degrees to the left or right. It would replace the stack filter inserter, which would become irrelevant if this suggestion were to be implemented.

Anyways, that basically sums up my suggestion. I feel like these new/improved inserters would help to make factory-building significantly less annoying.

[Optera]

Try Bob's Inserters. Except for more filter slots that mod has even more functionality than you suggested.

[Deadly-Bagel]

The game is supposed to be annoying though. All these features would encourage you to be lazy with your factory designs which is not good for long-term play. The vanilla game is simple enough that it doesn't need these sort of extended inserters. It's more fun to have to work around these sort of problems.

Bob's Mods on the other hand, wow. Try providing six components AND a fluid to a 2x2 building, regular inserters just don't cut it, and it also allows for some pretty cool setups.

[Optera]

Yes, Bobs inserters with vanilla makes you really lazy, or creative, depending on how you look at it. I mostly use Bobs inserters when I want to design ultra compact and need to place items diagonally around corners or simple the other side of a belt.