This here, in case there's any confusion (http://www.fallout3nexus.com/downloads/file.php?id=97).

1. Does this mod work okay with Broken Steel's increased level cap?

2. Can I use this mod with a game already in progress, and just level slower from that point? Or do I have to start over for it to work?

Yes it does work with broken steel, I have done it many, many times.There are those that say that it doesn't work and it is far from the best leveling mod around, and that you can't go past 20. That is hogwash, I have leveled past 20 numerous times using slower leveling.

Just to be fair,there ishttp://www.fallout3nexus.com/downloads/file.php?id=7565 which has slower leveling, also there is http://www.fallout3nexus.com/downloads/file.php?id=10597, which is yet another slower leveling mod that looks really good. Try one, try them all and see which one suits your tastes.

EDIT: yes you can use Slower Leveling with a previous save.

My Realism Tweaks does include my Reduced Quest XPR module, but that is not my primary slower leveling mod . . . it was made to be used with my http://www.fallout3nexus.com/downloads/file.php?id=7674

My Reduced_XPR mod slows down how fast you will level up. There are now several mods that allow you to reach higher levels, but my mod takes a different approach, while adding a bit of RPG balance.
- With my Reduced XPR, gaining the necessary Experience Points required to level up will now take roughly 3 to 5 times longer (depending on which esp you use).
- There are however, certain events that will cause you to level up, even though you are receiving fewer Experience Points. For instance, when you leave Vault 101, you level up to Level 2 (I only had 19 out of the required 200 XPs when I exited the vault, yet I still leveled up, since you receive 200 XP when you exit the Vault).
- it only edits the XPR values, so it is totally compatible with all DLC, and with most other mods.
- It should be placed near the end of your load order.

My Reduced Quest XPR module edits every quest that grants experience points when you complete the quest, and reduces the quest rewards point by 90%. For instance, you will no longer instantly level up when you exit vault 101. So it needs to load Before any mod that makes changes to any of these quests. This module is made to be used in addition to my Reduced_XPR mod. You can add and remove both my Reduced_XPRReduced Quest XPR module at any time.

barrettsfloyd, just because you did not have any problems does not mean that others haven't. My game kept freezing up upon leveling when I used the Slower Leveling mod, which was the main reason that I created my own mod. Edits to the iXPbumpbase appears to have caused problems for many uses (just read the comments in the Slower Leveling thread).

Now, can Experience Control also be added to an existing save? If they all can, I figure it'd be best for me to just try them all for a level or two on separate saves.