I have yet to get the dlc (psn) but in DM a lot of bugs existed (like where ED-E decides to become rabid robot) so my question is relatively simple.

What things are required to be done before playing honest hearts to prevent any major problems?
What things are recommended to be done before playing honest hearts?

and then the second question is:

What things should not be done before playing honest hearts (for example; before DM if you got the Ranger Sequoia you would not be able to open the hidden bunker as it would remain locked)
What things are recommended to not be done before playing HH?

if anyone could clear these up for me it would be greatly appreciated.

Well, the only thing I can think of is that, if you're prone to the "disappearing but still technically there companion" bug, to avoid hiring companions in the vanilla game. Because if they "disappear" (can't be fired), HH won't let you through, since it'll think you still have a companion with you...and the HH DLC doesn't boot companions automatically, like I hear DM did.

The rest...I don't think so far that anyone has a list of "it'll happen to almost everyone" stuff like you're thinking yet. Bugs & glitches vary per player/system etc & it hasn't been out very long for people to know what's what. You could try the fallout wiki entries on HH quests, tho, see if there's any big bug notes. Course that would be spoilery, but...up to you.

Get into the habit of observing targets for a few seconds before returning fire, that way you'll stand a better chance of not shooting a character that botches the whole questline.

pick up fav weapon types try to go for 3 found myself using most guns in HH tommy ftw and fav armour oh and make sure to have j rig perk also compleatly unrelated speaking to VINO i know who you are you owe me a doctors bag LADD

I'm also on PS3 and to prepare I crafted a Fire Gecko Tanned Hide and a Golden Gecko hide. The point of this is to bring them to Zion, along with the ingredients to make a Green Gecko Tanned Hide. Then (with a Survival skill of 90) I'll craft a Gecko Backed Leather Armor, reinforced. I'll never have to worry about Cazadors ever again.

Buy a pc heh... :brokencomputer: