95 850 GLT wagon: couple of questions

my Volvo has 181k miles. It got certain problem with front suspension
- steering.

1) Front struts are leaking severely. Does any one have any good
reference how to do it online and with pictures.
2) I jacked up the car at the front and I could feel that I could
rotate the wheel slightly around the front strut. It just goes here
and there then I take the wheel and twist it.

On the driver side I could see the loos ball joint. The wheel twirst
makes it move. What is the fix and possibly where could I find a good
reference of how to do it.

On the passenger side it was the tie-ro end (at least it feels loose
whey I do the twisting).

Maybe when the car is moving something else is loos but that is as far
as I could detect it.

What would be the solution. If I have to replace the control arm with
the ball joint and the tie-rod end do I do it in pairs usually?

3) I opened the spark wire cover with the 20-valve VOLVO lettering and
I found a lot of dirty oil there. Is my engine leaking there? How did
it get there? How do I fix it?

Today I replaced the radiator with Behr's unit, thermostat, and upper
and lower houses. My radiator was leaking and the thermostat was plain
broken when I took it out, althoug the engine did not overheet on the
20 miles trips.

All answers would be greatly appreciated.

PS. Mechanic said that sway bar is bad. How likely it is for the bar
to go bad and could it be that just changing sway/anti-roll bar links
and bushings.