If the CP is inside a building with no windows or open doorways players will not recognise the objective too easily. Generally you want the point to be visible or a focal point illustrated by details or a significant prop (like arena_nucleus's glowing whirly machine). If that fails, include some/more signs. Right now the only thing drawing people to this structure is that it's the only structure in the map.
Additionally, closed dynamic doors provide severe camping capabilities, notably for the demoman and the engi's sentry, but also soldier's, pyro's and heavies. Also, the smaller the doorway, the more effective door camping is. If a medic gets in their with his team mates.. the only thing stopping a team from rolling is limited ammo (an engi is sure to get a dispenser up in there though if they realise this), or if the enemy team manages an uber on a competent player to flush most of the defences out.
If a map
requires an uber of players for them to pass a certain location, the map is imbalanced.
Things to consider:
- More out-lying structures.
Buildings focus attention to within the map and onto enemies, as they block line of sight to the horizon. They also provide more interesting geometry and a scene for more prop details. Building shape and size also relate to the theme of your map which usualy revolves around a resource that the two teams are fighting over. They also provide oppotunities to flank enemies from within or around them.
- Variations in height.
Height variations provide a secondary method of breaking otherwise direct line of sight across large areas, preventing over powering of the sniper class, and the appearence of over scaling.
Height is a key part of TF2 gameplay mechanics. Including hills, ledges and balconies provides more interesting and dynamic combat experiences for players. The best refence for this would have to be cp_badlands.
- Do not test your map as a Scout.
Testing your map as a scout or demoman warps ones perspective on the overall size of a map. People tend to use scout so that they can traverse their map for bugs quickly before releasing it (demomen also tend to sticky jump to important areas). One needs to remember these are class specific perks: This often leads to class imbalances, particularly for the pyro and Heavy who are slower and lack speed perks.
If you can, test it as a spy. Testing as a spy gives you an average class speed to gage map size, but also makes you more aware of item drop placement as you can actively test cloaking distances. Testing as a soldier means you can test height variations, a slow class's speed and rocket jump boosts; this also means you are weary of health placement drops.