I'm a casual player, new to FS2, but have played some flight sims in the past.
Here's some feedback from what I've noticed:
Invert camera control
Currently is applied universally.
Desire separate cockpit and external camera control, as they feel different.
Cockpit button Tool tip
Currently when mouse over a control, the cursor changes, but no tooltip appears.
Desire tool tips to highlight what the button is.
Can be very hard to read the writing on screen or at night.
Tool tip could also show current value eg. 'HDG 275' or 'Light Off' or 'Throttle 72%'
Clear cockpit button state
Currently it is difficult to tell what state some buttons are in. They don't light up or have a clear 'pushed' visual effect.
Desire clear 'on' and 'off' state.
Mouse control for cockpit
Currently mouse + left button moves the camera AND left mouse button operates buttons
Currently mouse wheel changes some knobs.
Desire something like:
Hold Right mouse button + Move to look around cockpit / move camera
Hold Right mouse button + mouse Wheel to zoom in & out
Left mouse button and mouse wheel can now operate controls
Currently views cycle Next + Previous. With so many views makes it hard to quickly return to 'known' view.
Desire Better view control, for example, '1' always returns to the cockpit, never cycles.
Currently [Off, On]
Desire [Off, External, Always]
In cockpit, not realistic, but external camera is fine and pretty.
Currently you can't tell which menu item you mouse is over. Only keyboard shows a highlight.
Desire visual states for UI menu buttons eg. Pointer Over at least.
Set time of day
Currently only set by UTC.
Desired: Keep showing UTC, just also show local time where the aircraft current position is.
Or show mid day -> mid night indicators so light levels can be selected intuitively.
Bug?: Can't return to pilot seat, stuck in copilot seat
Pressing '1' or '2' cycled various views but never returned to the original pilot seat.
Work around - swap planes and back, now camera can cycle all seats
Bug?: Aeleron trim
Got stuck, only banked left hard, no amount of 'right' would return it.
Work around - swap planes and back reset it.
Bug?: Settings Controls UI overlap
'Logitech Extreme' joystick config menu button overlaps 'Game Control' button.
Bug?: Approach guides sometimes visible
I've had the green 'box' guides not be visible near the aircraft, but visible in the distance or behind.
Also completely disappear for a while, then reappear.
I was flying in very close proximity to them the whole time in all cases.
Thanks for listening.
I realize FS2 is a work in progress.
I am enjoying the flight.