No, Seneca has a fuel injection system which doesn’t suffer from vapour icing.
If you pitch up in a Seneca the speed IAS will decrease, because of the constand speed drive (in the propeller hub).
The propellers want to maintain the original RPM. Therefore the blades will go to a more fine blade setting.
Alternate air is an alternate source of air, it can for example be used during ice, when the normal filter is blocked to have a backup source available.
Alternate air is unfiltered air and should not be used during ground operation because the unfiltered air may contain dust and other contamination.
Only hydraulic gear.
17KTS
Seneca uses MOGAS (red) or AVGAS (Blue)
Easier for the company in regards to training, maintenance and spare parts as you only use one type of aircraft.