Ability to open ROM files directly

While it isn’t true for all ROM types, ROMs of certain game systems store sprites in uniform format which allows easy sprite hacks with tools like YYCHR as long as you don’t need to change the palette (then you need to disassemble the rom and figure out where the palette is stored). I’d like to be able to open these ROM files directly in PM as while YYCHR is a workable solution, it isn’t most easy to use. It’d need some import options so you won’t accidentally overwrite the code (represented in the ROM if displayed as graphics as noise-like pattern) to set first/last offset of graphics data which may be different in various ROM files (there should be a little preview window of area around end offset and initial offset so it is easy to set the offsets properly if you don’t know these by heart) and same for export so it can be exported as IPS and integrated with a rom using a standard IPS patcher.

This beyond the scope of typical file i/o and should be handled by separate data extraction/assembling tools for such a file type.
But you could create file i/o plugins to achieve this: https://www.cosmigo.com/pixel_animation_software/plugins/developer-interface

I’ll try, though I don’t know if it will work with Lazarus (I don’t like C/C++ too much, though pretty OK with managed languages like C# or Java with which I won’t be able to do such plugin so Lazarus/Free Pascal is the only option since I can’t afford Delphi license).

If they support standard Windows DLL interfaces and this is a must for any compiler then it works. You don’t need to use C++