How to effectively transfer work files from MacBook Pro to iPad Pro for home use?

Assuming that both your Mac and iPad are signed-in to iCloud with the same AppleID, any files that you store in your iCloud storage will be accessible to both devices no matter where you are. All you need is an internet connection to access your iCloud storage.

As for the Apps that you specifically mention, they are certainly supported and available from the Apple App Store:

Pixelmator

https://apps.apple.com/app/pixelmator/id924695435

Filmora: Al Video Editor, Maker

https://apps.apple.com/app/filmora-ai-video-editor-maker/id1019382747

Filmora HD-Vlog Video Creator

https://apps.apple.com/app/filmora-hd-vlog-video-creator/id1459336970

If any changes to the title or content of your post have occurred, this will have been the site Moderator - not me.

Contributors here are all end-users, just like you. Contributors (such as myself) can only reply to a thread; we cannot make any changes or edits to anything other than our own post/reply.

As for having access to an internet connection, this is only required to access and download a copy of the file stored in iCloud. To be clear, once downloaded to a device, you don't require a continuous internet connection.

Speaking of personal experience, I have not encountered any file corruption when transferring files via external USB storage. Perhaps you can provide more information about how iPadOS "scrambles" file handing.

As for suitably as a laptop replacement - acknowledging that a minority of tasks that can be performed on a Mac or PC are difficult or impossible to achieve with iPad. However, balancing this observation, the same is true in reverse; an iPad is equally capable of some tasks not possible with a traditional laptop). I have, by choice, largely transitioned to my iPad Pro as my main computer. YMMV.

Perhaps if you outline how, where and when you are experiencing difficulties, I or other contributors may be able to offer specific guidance.