[HELP] Creating/Modifying a ROM based on stock, is it as easy as it sounds? - Android Q&A, Help & Troubleshooting

I've been searching for a way to create a debloated ROM based on stock, since there are no developers working on any type of custom ROM based on AOSP or any type of ports.
It's too complicated for me to understand really (port a custom ROM based on AOSP/Lineage OS) since I have no knowledge of any type of code.
What I have been able to learn, however, is to modify a flashable zip to add/remove/delete anything you want by modifying the "updater-script" file and flashing it via TWRP (a custom recovery)
With this, I have been able to remove bloatware that really slowed down the device and I am loving it
But now, what I want to do is to create a flashable zip, debloated ROM based on stock, not just have a flashable zip to remove apps that you add via an Odin flash (I have a Samsung device)
Is it as easy as extracting all the contents of system.img (done), removing the folder of the apps you don't want and add the following commands in the updater-script?
Code:
run_program("/sbin/busybox", "mount", "/system");
package_extract_dir("system", "/system");
run_program("/sbin/busybox", "umount", "/system");
Or is there more to it than that? I feel like it's way too easy to be the case.
I know there's ASSAYYED's KITCHEN to ease up on making a debloated stock ROM, but the PC I use detects it as malware and eliminates the exe file, I do not have administrator rights on this PC.
Everywhere I search all point towards ASSAYYED's Kitchen, unfortunately and I really want to learn a bit more and maybe create a flashable ROM based on stock

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Went ahead and tried it...
Sooo... I've been downloading various debloated ROMs based on stock from various Samsung devices and I've gotten a general idea of how to edit my code... a little bit.
I'm having a bit of trouble getting it to run and I think it has to do with permissions... because when I remove the ones I have added it doesn't boot at all it just stays on the initial screen but when I add them I atleast get to the Samsung logo.
Would anyone take a look at my updater-script and let me know if I'm missing something?
Code:
unmount("/system");
ui_print("Let's beggin!");
sleep(1);
ui_print("Formatting /system...");
format("ext4", "EMMC", "/dev/block/platform/mtk-msdc.0/11230000.msdc0/by-name/system", "0", "/system");
sleep(1);
ui_print("Mounting /system...");
mount("ext4", "EMMC", "/dev/block/platform/mtk-msdc.0/11230000.msdc0/by-name/system", "/system");
sleep(1);
ui_print("Installing debloated ROM!");
package_extract_dir("system", "/system");
ui_print("Done!...");
sleep(1);
ui_print("Setting permissions...");
set_perm_recursive(0, 0, 0755, 0644, "/system");
set_perm_recursive(0, 2000, 0755, 0755, "/system/bin");
set_perm(0, 0, 0755, "/system/bin/install-recovery.sh");
set_perm(0, 3003, 06755, "/system/bin/ip");
set_perm(0, 1000, 0750, "/system/bin/iptables");
set_perm(0, 3003, 02750, "/system/bin/netdiag");
set_perm(0, 3004, 02755, "/system/bin/ping");
set_perm(0, 2000, 06750, "/system/bin/run-as");
set_perm(0, 1000, 0750, "/system/bin/tc");
set_perm_recursive(1002, 1002, 0755, 0440, "/system/etc/bluetooth");
set_perm(1000, 1000, 0640, "/system/etc/bluetooth/auto_pair_devlist.conf");
set_perm(0, 0, 0644, "/system/etc/bluetooth/iop_device_list.conf");
set_perm(1014, 2000, 0550, "/system/etc/dhcpcd/dhcpcd-run-hooks");
set_perm(0, 2000, 0550, "/system/etc/init.sec.boot.sh");
set_perm_recursive(0, 0, 0755, 0555, "/system/etc/ppp");
set_perm(0, 0, 0555, "/system/etc/ppp/ip-up-vpn");
set_perm_recursive(0, 2000, 0755, 0644, "/system/vendor");
set_perm_recursive(0, 0, 0755, 0644, "/system/vendor/lib");
set_perm(0, 2000, 0755, "/system/vendor/media");
set_perm_recursive(0, 2000, 0755, 0755, "/system/xbin");
ui_print("Extracting boot image...");
package_extract_file("boot.img", "/dev/block/platform/mtk-msdc.0/11230000.msdc0/by-name/BOOT");
ui_print("Installation complete!");
sleep(1);
unmount("/system");
It must be noted that the only thing I have in the system folder is everything I extracted from system.img from the stock ROM I downloaded from Sammobile. I also added the boot.img