Jump gates are formed in a particular location within a margin of error;
it's not like throwing a newspaper at a door. The gate might form in front or
behind.
How many ship-mounted generators (which are inside the hull) have you
seen to be able to say that they can be of any shape? How do you know they're
different shapes? To my knowledge, we've never shown a ship-mounted
generator.
A ship-mounted generator can open a fairly small opening, and do it maybe
twice or three times within a 24 hour period or so, because of the massive
energy requirements involved. The rails and chargers along the way are
designed to facilitate a *lot* of travel in and out during a day, and to make
the entry a little easier, not as abrupt as a ship-mounted jump.
We simply haven't shown a jump gate from the side or back yet. We have
talked about this at some length, and probably will do so at one point next
season.
Why doesn't it manifest itself as a sphere, and why a vortex? Because
the rails are at opposite sides one from the other. They project out opposing
lines of force which in repelling one another create a tunnel into hyperspace.
The lines of force on a ship-mounted system are not visible to the human eye,
and are less stable, hence more uncomfortable when entering (see above).
In-gates and out-gates *are* identical. The only difference is in
coloration, based on red-shift.
The vortex is *not* an energy booster, which answers that question.
Seems to me that most of your questions come from incorrect assumptions
and insufficent consideration of the issues at hand, not really thinking
things through, rather than logical or scientific flaws on our part.
Just one man's opinion.
But it's canon.
jms