Found a low level dungeon I had made

   While looking through some of my random junk I found some maps I had drawn at some point along with my copy of World Builder's Guidebook. Later I will be using the world I made for one of my letters but before that I decide to put up my dungeon I found. First I scanned in my originals which for completeness here they are:

Now here is my new improved version that I did because despite being a mine it did not look like a mine, not that it does now but its looks like the start of a mine now.

While technically the new mine for a dwarf city I was making called Kalentar it can be anywhere you would put a mine. The flavor I have for it is that when digging a new mine the dwarves hit a tunnel and where set upon by a number of kobolds so they retreated back and would like you to go clear them if you can. They mention before they send you in that the locked room is empty. There are exactly 20 kobolds in the place. The numbers are encounters and here are what they are:
1. 1d4 kobolds are present with bows and quiver with 10 arrows each along with a dagger. They will fight till there is one left and once only one is left it will try to run away and alert others.
2. The secret doors to the room are just regular doors behind some wall hangings so if they search at all they should find them. The room contains a couple chests in it. One is unlocked and contains a potion of cure light wounds with 1d8 coppers. the other chest has a simple lock and contains 1d8+2 silver and a 10% chance of another potion of cure light wounds. There is also a barrel of beer that is mostly empty. the room appears to have been used as a break/hide from the overseer room.
3. The door has a simple lock on it and the room itself contains nothing much of note.
4. The walls are secret doors that while not good enough to pass close examination are good enough that the party could walk past them without noticing.There is a kobold behind both of the doors but if they hear the party trying to enter the locked room one of them will go to alert the rest. If one of the kobolds from the first encounter escaped and made it past here they will not. The kobolds will let the party goes past them then sneak up behind them to attack as the fight the kobolds in the next room.
5. There are three kobolds hanging out here. If a kobold is able to get warning to them, two of them will be hiding in the corners so that they can not be seen. If the kobold that warns them is from the first encounter then it will have passed its bow and arrows off to one of the kobolds here before going on.
6. Just a kobold hiding behind some walls. Lets the party pass and attacks them from behind when they get to number 7. If the party found the hidden doors at 4 they have a better chance to find this one and get a check just by passing near it.
7. A kobold hiding in the corner. If a kobold was able to get through and warn the rest it will also be here waiting.
8. Both 8's are platforms with a kobold on top. The kobold both have bows and a quiver with 10 arrows and a dagger. there are also 20 arrows on the platform but if they need them they have to take a turn to get them. If the kobolds are warned then there will also be a kobold with a sword on the ground. In encounter 1 if there was less then 4 kobolds then there will be the missing ones here as well split evenly between the two platforms and if an odd number they are at the platform closer to encounter 7 and they are armed with a bow and quiver with 10 arrows each along with a dagger.
9. This is the sleeping area for the kobolds. If not warned then there are four kobolds here along with how ever many less then 4 in the first encounter. Each kobold here has a 60% chance of being asleep. Any here will only have a dagger on them. There is on the wall next to the door swords for each and bow and quiver with 10 arrows for each of the kobolds from the first encounter. If warned there are two kobolds with swords ready to attack any non-kobold that enters.
10. The commander and sub-commander live here and will be in this room and their treasure is in the chest here. They are well armed with a sword, shield, and the commander has better armor. If warned they will be ready. There is a chest with a simple lock containing treasure appropriate for the commander and sub-commander as well as the shaman type from encounter 11.
11. This is the room of a shaman type. The kobold will have some kind of magical ability and if warned will go join the commander and sub-commander. His treasure is in the chest in the commanders room.

   Please comment on it because its basically the first dungeon I have ever made. I think it would be a low level dungeon but I do not know how low. As for what I plan to do with it is if they don't find the secret door that leads off the map is that reinforcements will come.