I read that using markfordelete is bad to use and can end up causing ctds...they said to use disable.....is this true..i recently was using markfordelete and started having crash round falkreath and lakeview manor.

Yes. Deleting a reference that another mod tries to refer to can/will cause CTDs. You're better off disabling the object/reference instead. Use TES5Edit to remove your deletions and disable them instead.

Markfordelete is a console command. It's effects are irreversible. Best to simply not do that.

Disabling can be reversed, but only if you keep track of what you're disabling.

There should be no real reason to use console commands like that while playing though. It's not a very good idea because it can still cause problems with CTDs that you'd then be unable to resolve.

How do you move stuff around in your house or what not...whats the safest way......i just got jaxonz postitioner...is that ok to use?

I was also using markfordelete to get rid of corpse and ashpiles that seemed to be taking forever to cleanup...is disable the best on them to?

Using 'markfordelete' on ash piles should be safe, because they use a non-unique Reference ID (the first two digits are "FF"). You just have to be very careful not to accidentally delete something else by mistake. Most ash piles eventually do clean up on their own (which can take up to 30 days), so it is typically unnecessary to delete them. However, there are a select few that never will disappear due to engine issues that Bethesda never addressed. Since those kinds of things tend to bother me, I have used 'markfordelete' on those ash piles without issue.

As far as corpses go, it is definitely best to avoid using that command on those. Using disable would be much safer (as others have already mentioned).

What about console command "recycleactor"? Recently I ran into a problem with certain npc follower getting stuck with a package going rogue (trying to reach certain destination that got destroyed by script), or to be more specific, will forever trying to reach a destination that is no longer there.

I was tempted to just to disable (if not outright markfordete this npc) this npc, and spawn another copy using the placeat command.

Please let me know of the most appropriate way to disable a "travel" package assigned to a NPC if there is one.

Thanks.

Recycleactor should be fine, but I would only use it on not-so-important NPCs.