Removing too many leaves can cause weak growth due to the reduction of energy production, otherwise your plant appears quite normal. The red stems can be caused by light burn, also caused by leaf removal. Tropicanna Poison Fast Version is also a strain with red flowers (80% probability) so this too could account for the red stems. You should also remove the fallen/trimmed leaves from the base of the pots and floor, otherwise they can be prone to fungal/mould attack, especially the ones on the moist surface of the pots. If you are really concerned with the weak stems, extra calcium may help, however, your plants seem fine to me.
Hope this helps,....... Organoman.