Re: short channel effets
the channel length modulation, which is valid also for long channels, is very relevant in short channel MOSTs. In the simple parabolic equation, the lambda coefficient is inversely proportional to L, so for very short transistors the drain current increment with Vds is decisively relevant.
Body effect is not a phenomena involved only in short, but in all type of MOS.
Velocity saturation is off course another important effect, which decreases the effective mobility of the transistor. It depends on the technology, like the other effects. Hot carrier phenomena occur especially for high VDS, over 2 V.
There is another effect, namely DIBL (drain induced barrier lowering), which is not easy to take into account with simple modelling.
However, the channel length modulation is very relevant, and quite easy to take into account.