Tileset Help and Advice?

Tileset Help and Advice?

Alright, I've had a heck of a time getting something that should be simple, work.

So, for the longest time I was using a fixed resolution "system" in myt game, where it would always run @ 768 x 432 (it seemed to scale well into 16:9 resolutions). Recently I've been toying around with a dynamic system (and I'm not even sure if I'm going to keep it, as it's caused so many issues for me). Where the game will scale to 4:3, 16:9 or 16:10 and effectively switch resolutions based on the resolution of the monitor it's running on.

Seems simple enough, right? ...Right? I guess not because when doing so I would get graphical glithces and eventually (after fixing those) I had seams in my tiles when in motion or when the game was scrolling from left to right or right to left. Obviously that couldn't stand so after doing some research and trying to understand this article:

https://www.yoyogames.com/tech_blog/8

I finally asked around and eventually found a way to fix the seams, but not for all of the tiles. I'm having an issue with a piece that is not the same size as the other tiles, basically it's taller and wider. I'm just not even sure what to do. I wasn't aware that managing tiles was such a hassle. The tileset I am using is shown at the bottom and after finding out what to do I can get the five tiles that are stacked on top of each other and the one to the left to work just fine, but when imported into gamemaker I have to tell it exactly where the tiles are and sometimes they do not line up right. I have no idea how to manage the tiles to the right either. I guess I'm just asking for help or advice, does anyone have a system set up for nightmares like this? If each and every tile I had was the same size and shape (like 32x32) I could manage, but not all of the ones I come across are.

Do you think I should seperate each one so they are all the same size and shape? The ones that aren't just cube shaped I mean?

Candy Tileset