The object placer has a lot of options, to handle all these option easily 
I reccomend that you use batch files. 

Files used:

DMOP.EXE        Object placer, the executable file that does all the actual 
                creation and object replacement.

DATRWOP1.DAT    Configuration files that allow the object placer know
and             what the names, codes, angles, and other stuff in DOOM1
DATRWOP2.DAT    and DOOM2 are.

DOOM.WAD        DOOM1 IWAD or Main wad file
DOOM2.WAD       DOOM2 IWAD or Main wad file
ANNEX.WAD       A small patch wad, really pretty good for its size,
                can be used to create a new patch wad.

Command line arguments:

DMOP [CONFIG FILE] [IWAD or PWAD] [RW FILE] [NEW WAD] [OLDLEVELNAME] 
          [NEWLEVELNAME] [#ofobjects] | [Random#seed]

[CONFIG FILE]   DATRWOP1.DAT Configuration files that allow the object 
                placer know and what the names, codes, angles, and other 
                stuff in DOOM1 DATRWOP2.DAT and DOOM2 are.

[IWAD or PWAD]  DOOM.WAD, DOOM2.WAD are IWADs, ANNEX.WAD is a patch 
                wad.

[RW FILE]       Random world configuration file.  This file which is 
                compatible with the RANDOOM file format, contains the
                proportions and types of objects to place in the new level
                as well as some other special settings.

[NEW WAD]       The name of the new wad file to create, such as TEST1.WAD for
                example.

[OLDLEVELNAME]  The name for each level as they are used in the game for
                DOOM1 these names were E1M1, E2M5, E3M9, and in DOOM2 the
                names are MAP01, MAP15, MAP32.  Notice all caps in the name
                case is very important and must match the format set by
                the WAD file designers of the game.  If you are unsure what
                level the Patch wad you are modifying replaces, use DEU or 
                some other editor to give you this information, most patch
                wad files replace E1M1 or MAP01, but not always.

[NEWLEVELNAME]  Same as [OLDLEVELNAME] except that it tell the object placer
                what level you want the patch WAD file to replace.

[#OFOBJECTS]    The number of objects to place in the new patch wad, this 
                value can be a percentage or a fixed integer value.  Valid
                examples are 100P (100%), 200 (200 objects).  The P means
                % percentage, the percent sign could not be used because this
                would interfere with DOS batch file processing.

[Random#seed]   This is any number from 0-65535 inclusive.  It is a seed value
(optional)      for the random number generator, and can be used to recreate evels with the minimum amount of information of the
                [CONFIG FILE], [IWAD or PWAD], [RW FILE], and the Random 
                number seed.  The random number seed is optional, if you
                do not provide one, a new seed will be created using you 
                computer's clock values, and this number will be saved in the
                file seed.sav, for future use.


Creating a new set of maps.

You can create a new set of maps or levels very quickly using the Object 
placer, but you might ask how to I load all these maps into DOOM?  You have
several options:

1. Create a new composite DOOM wad, this require an external program like 
DEU.

2. At the DOS command line specify the Wad files like this:

DOOM -file WAD1.WAD WAD2.WAD WAD3.WAD ...

Using either method DOOM will load the files in the sequence specified
by each WADS level name, which is contained within the WAD file.  The object
placer batch file automatically puts the level name into the newly created
Patch wad.

Creating playable set of levels:

Many DOOM levels can be exceedingly difficult in the hard modes, even when 
the RW files give the player a variety of weapons.  The generator takes care
not to place to many enemies near the player one start position, unless the 
original Wad file put a lot of enemies near the player.  The generator, 
generally but not always follows the layout of the original WAD file when
placing objects into the new map.  If it always followed the original design
things would get boring so it can deliberately reweight, redistribute, and 
randomly pattern object placement, I call this volatility of placement.

To overcome the volatility or just plain difficult patch wad you must 
have built up enough weaponry and health to survive within the level 
to find more weaponry and health.  To achieve the buildup the level must 
start from an easy level of play to a difficult level of play in the final 
levels.  The original DOOM E1M1 thru E1M3 does this, the first level E1M1 
is very easy and it gives you the shotgun, megarmor, and full health when 
you finish.  In the following level you can get the Chaingun, Chainsaw, 
and Supercharge.  By the time you get to E1M3 you are at maximum health 
and are very well armored so you can take on that level effectively.  

So I reccomend that in any set of levels in which the user has to start 
from scratch, make sure that the first level is short, has at least one 
heavy weapon, and only a modest number of enemies.  To help you with this 
I have rated the RW files internally, read the documentation at the top of 
the RW file to help you decide which RW to use initially and which should  
appear later in the sequence.  

I have to leave it up to you to decide which levels or patch Wads are easy 
and hard, I cannot rate them for you, because I don't have every patch wad 
in this world.