Sorry to hear about your displeasure with Forest Hill station and the performance of the train service. i will try to address your points as best i can.
Regarding the station being an eyesore. Due to the station becoming the property of LOROL and the east london line in september Southern will not be doing any improvement works. The Station buildings themselves are owned and maintained by network rail but it would be up to the TOC to suggest improvements. i have been "in charge" of Forest Hill for the last 7 months and have seen the implementation of the hanging baskets and bike sheds but we havent been able to complete any building work. This is the same for shelters and any other improvement works the only additional bits we can do at the moment is Paint Jobs. However i have been to a few meetings regarding the construction of lifts at the station however this is in its very early stages and i wouldnt be able to give you a date on when this work will take place if it does.
The side gate has been closed (perry vale) due to our contractors completing works so that CUBIC can install new gateline arrays, cctv and ticket vending machines - we are now waiting for CUBIC to come and complete the works and dont have the manpower to man the side gate as before however this is considered on a weekly basis and where possible we will endeavour to do so.
Train performance has been very up and down since the introduction of the new timetable in december and completly agree that it hasnt really been acceptable but believe me we are working to improve this as much as we can. Overcrowding on your part of the railway is alos a major issue Southern uses all the stock it currently has which we know isnt quite enough but people at all levels are aware and again we are working on it but there are no easy or quick solutions
Reading that back it doesnt come across as positive or customer friendly. Unfortuatly we are in a position where we soon lose though stations so spending money isnt really an option however if you do encounter any problems at the station such as ponding etc please make one of my members of staff aware or me and we will deal with the problem as soon as possible.