As there are 19 pages to the thread I don't know if anyone has given advice on the Birmingham area. For passenger only services you have Birmingham New Street and Birmingham Moor Street. I do not recommend Birmingham Snow Hill as not all Chiltern services run through Snow Hill.
TOCs serving New Street are Virgin, Cross Country, West Midlands Railway, London NorthWestern Railway and the successor to Arriva Trains Wales.
TOCs serving Moor Street are West Midlands Railways and Chiltern Railways. Moor Street station is managed by Chiltern.
The only loco hauled services will be Chiltern Class 68 + DVT into Moor Street.
Leave New Street Station by the Stephenson Street entrance and you will find West Midlands Metro trams. A short run to Jewellery Quarter is a cheap fare of £1 each way. Jewellery Quarter as well as being a tram stop is also a station on the Moor Street/Snow Hill line to Stourbridge so you could return to the city centre by train if you wish.
For freight you will need to move out of the city centre and that has mainly fallen below my radar so I can't really advise a good vantage point. For example through my local station the only freight working is the Tesco train to Daventry in the late evening. Kings Norton is a possibility for freight on the Camp Hill line but many of those are shown as 'runs as required'.