These are the mods I'm using:
Active Mod Files:
Spoiler
00 Oblivion.esm
01 All Natural Base.esm [Version 1.3.1]
02 Francesco's Leveled Creatures-Items Mod.esm [Version 4.5bSI]
03 Francesco's Optional New Items Add-On.esm [Version 4.5bSI]
04 Francesco's Optional New Creatures Add-On.esm [Version 4.5bSI]
05 Oscuro's_Oblivion_Overhaul.esm [Version 1.33]
06 FCOM_Convergence.esm [Version 0.9.9a7]
07 Unofficial Oblivion Patch.esp [Version 3.3.6]
08 Oblivion Citadel Door Fix.esp
09 DLCShiveringIsles.esp
0A Unofficial Shivering Isles Patch.esp [Version 1.4.3]
0B FCOM_FrancescosItemsAddOn.esp [Version 0.9.9]
0C Natural_Weather_by_Max_Tael.esp
0D Natural_Weather_HDR_by_Max_Tael.esp
0E Natural_Habitat_by_Max_Tael.esp
0F All Natural.esp [Version 1.3.1]
10 All Natural - SI.esp [Version 1.3]
11 Enhanced Water v2.0 ND.esp
12 Enhanced Water v2.0 HD.esp
13 Natural_Water_by_Max_Tael.esp
14 All Natural - Real Lights.esp [Version 1.3]
15 Living Economy.esp
16 Living Economy - Items.esp
17 Cutthroat Merchants.esp
18 Display Stats.esp [Version 2.0.1]
19 Quest Log Manager.esp [Version 1.3.2]
1A Dynamic Map.esp [Version 2.0]
1B Map Marker Overhaul.esp [Version 3.9]
1C Map Marker Overhaul - SI additions.esp [Version 3.5]
1D Enhanced Hotkeys.esp [Version 2.3]
1E DLCHorseArmor.esp
1F DLCHorseArmor - Unofficial Patch.esp [Version 1.0.6]
20 DLCOrrery.esp
21 DLCOrrery - Unofficial Patch.esp [Version 1.0.4]
22 DLCVileLair.esp
23 DLCVileLair - Unofficial Patch.esp [Version 1.0.7]
24 DLCMehrunesRazor.esp
25 DLCMehrunesRazor - Unofficial Patch.esp [Version 1.0.5]
26 DLCSpellTomes.esp
27 DLCSpellTomes - Unofficial Patch.esp [Version 1.0.1]
28 DLCThievesDen.esp
29 DLCThievesDen - Unofficial Patch.esp [Version 1.0.9]
2A DLCThievesDen - Unofficial Patch - SSSB.esp [Version 1.0.4]
2B Francesco's Optional Files.esp
2C Bob's Armory Oblivion.esp
2D Cheat Bob's Armory Oblivion.esp
2E FCOM_BobsArmory.esp [Version 0.9.9]
2F Oscuro's_Oblivion_Overhaul.esp [Version 1.33]
30 OOO-Water_Weeds.esp [Version 1.33]
31 OOO-Map_Markers_Stock.esp [Version 1.33]
32 OOO-No_Guild_Ownership.esp [Version 1.33]
33 OOO-DLT_Remover.esp [Version 1.33]
34 OOO-Container_Trap_Instant_Effects.esp [Version 1.33]
35 DLCBattlehornCastle.esp
36 DLCBattlehornCastle - Unofficial Patch.esp [Version 1.0.6]
37 DLCFrostcrag.esp
38 DLCFrostcrag - Unofficial Patch.esp [Version 1.0.5]
39 Knights.esp
3A Knights - Unofficial Patch.esp [Version 1.1.1]
3B Natural_Vegetation_by_Max_Tael.esp
3C Harvest [Flora].esp [Version 3.0.0]
3D Harvest [Flora] - Shivering Isles.esp [Version 3.0.0]
3E Harvest [Flora] - DLCVileLair.esp [Version 3.0.0]
3F Harvest [Flora] - DLCFrostcrag.esp [Version 3.0.0]
40 HUD Status Bars.esp [Version 4.2.1]
41 Francesco's Slower skills x1.5.esp
42 Level_Rates_Modified_x3.esp
43 Corean_hair_for_Original_race.esp
44 Francesco's 7 days respawn time - 1-16 day lenght rescale.esp
45 OOO-Respawn_Week.esp [Version 1.33]
46 OOO-Magic_Script_Effect_Fix.esp [Version 1.33]
47 Bashed Patch, 0.esp
01 All Natural Base.esm [Version 1.3.1]
02 Francesco's Leveled Creatures-Items Mod.esm [Version 4.5bSI]
03 Francesco's Optional New Items Add-On.esm [Version 4.5bSI]
04 Francesco's Optional New Creatures Add-On.esm [Version 4.5bSI]
05 Oscuro's_Oblivion_Overhaul.esm [Version 1.33]
06 FCOM_Convergence.esm [Version 0.9.9a7]
07 Unofficial Oblivion Patch.esp [Version 3.3.6]
08 Oblivion Citadel Door Fix.esp
09 DLCShiveringIsles.esp
0A Unofficial Shivering Isles Patch.esp [Version 1.4.3]
0B FCOM_FrancescosItemsAddOn.esp [Version 0.9.9]
0C Natural_Weather_by_Max_Tael.esp
0D Natural_Weather_HDR_by_Max_Tael.esp
0E Natural_Habitat_by_Max_Tael.esp
0F All Natural.esp [Version 1.3.1]
10 All Natural - SI.esp [Version 1.3]
11 Enhanced Water v2.0 ND.esp
12 Enhanced Water v2.0 HD.esp
13 Natural_Water_by_Max_Tael.esp
14 All Natural - Real Lights.esp [Version 1.3]
15 Living Economy.esp
16 Living Economy - Items.esp
17 Cutthroat Merchants.esp
18 Display Stats.esp [Version 2.0.1]
19 Quest Log Manager.esp [Version 1.3.2]
1A Dynamic Map.esp [Version 2.0]
1B Map Marker Overhaul.esp [Version 3.9]
1C Map Marker Overhaul - SI additions.esp [Version 3.5]
1D Enhanced Hotkeys.esp [Version 2.3]
1E DLCHorseArmor.esp
1F DLCHorseArmor - Unofficial Patch.esp [Version 1.0.6]
20 DLCOrrery.esp
21 DLCOrrery - Unofficial Patch.esp [Version 1.0.4]
22 DLCVileLair.esp
23 DLCVileLair - Unofficial Patch.esp [Version 1.0.7]
24 DLCMehrunesRazor.esp
25 DLCMehrunesRazor - Unofficial Patch.esp [Version 1.0.5]
26 DLCSpellTomes.esp
27 DLCSpellTomes - Unofficial Patch.esp [Version 1.0.1]
28 DLCThievesDen.esp
29 DLCThievesDen - Unofficial Patch.esp [Version 1.0.9]
2A DLCThievesDen - Unofficial Patch - SSSB.esp [Version 1.0.4]
2B Francesco's Optional Files.esp
2C Bob's Armory Oblivion.esp
2D Cheat Bob's Armory Oblivion.esp
2E FCOM_BobsArmory.esp [Version 0.9.9]
2F Oscuro's_Oblivion_Overhaul.esp [Version 1.33]
30 OOO-Water_Weeds.esp [Version 1.33]
31 OOO-Map_Markers_Stock.esp [Version 1.33]
32 OOO-No_Guild_Ownership.esp [Version 1.33]
33 OOO-DLT_Remover.esp [Version 1.33]
34 OOO-Container_Trap_Instant_Effects.esp [Version 1.33]
35 DLCBattlehornCastle.esp
36 DLCBattlehornCastle - Unofficial Patch.esp [Version 1.0.6]
37 DLCFrostcrag.esp
38 DLCFrostcrag - Unofficial Patch.esp [Version 1.0.5]
39 Knights.esp
3A Knights - Unofficial Patch.esp [Version 1.1.1]
3B Natural_Vegetation_by_Max_Tael.esp
3C Harvest [Flora].esp [Version 3.0.0]
3D Harvest [Flora] - Shivering Isles.esp [Version 3.0.0]
3E Harvest [Flora] - DLCVileLair.esp [Version 3.0.0]
3F Harvest [Flora] - DLCFrostcrag.esp [Version 3.0.0]
40 HUD Status Bars.esp [Version 4.2.1]
41 Francesco's Slower skills x1.5.esp
42 Level_Rates_Modified_x3.esp
43 Corean_hair_for_Original_race.esp
44 Francesco's 7 days respawn time - 1-16 day lenght rescale.esp
45 OOO-Respawn_Week.esp [Version 1.33]
46 OOO-Magic_Script_Effect_Fix.esp [Version 1.33]
47 Bashed Patch, 0.esp
I've disabled anything in FCOM that could conflict with OOO and nothing.
I'm at a loss to figure out why adding just a small numbers of mods like this is so bloody hard with this game. It certain isn't this bad or unintuitive for Morrowind or FO3.