Let me try, memory rusty liao 
3. Berth A2 and A3, the end-on berths could not accomodate
artics to park, therefore it was moved to a seldom used alighting
saw-tooth berth at the end of the interchange. Also, another reason
was due to the high frequency of 811, and frequent reversing at
that berth causes a bottleneck of traffic into the interchange.
Btw, as far as i remember, 811E rarely existed during those times
unless changing shifts, Only after the artics was introduced into
811 did they started to have the current deployment (1 811E, 1 811)
for the former 805 route.
4. Not too sure but i think its B7, now replaced with 854E.
5. 3 High capacity feeders services near the exit of the
interchange = JAM, also, during the time 800's berth was together
with 804/806, most of the time it will board at the end of the
sawtooth berths to allow 804/806 to come in (nearer towards the
public phones).
6. 854
7. Walk to scan cards very far.
8. 520 will make one big loop around yishun before continuing
back on Ave 2 at khatib. The other trunks simply start their
journey directly on Ave 2.
3. Correct. Though got other reasons. xD
4. Wrong.
5. Correct.
6. Correct.
7. Correct.
8. Somewhat correct.
Anyone wanna try 1 or 2? xD
