Personal opinion, Yes It is necessary to know the drawing engineer by hand. To gain experience in imaginative of the figure or shape. But after a period of experience and practice, the engineer does not need to draw the hand except in a specific place.
Depending on the level and skill of the individual in preliminary studies, students will be taught the engineering drawings by hand and taught drawing using engineering drawing programs
It depends on your purpose and the area of your work, I prefer to work with CATIA but solidworks is OK too and is much easier than CATIA. You can use AutoCad but i Do Not recommend to you.
Depends on the disciple you belong to. It may be fruitful for civil and architecture, where the drawings play an important role to interpret the designs. But as far as other disciplines such as computer, electronics etc are concerned, i dont think there is a role of engg drawing. The CADD softwares are enough.