Re falls:
Mostly from memory (i.e., I'm not going to go back through 18 years worth of rule changes to verify exactly which year each rule change was introduced), the changes were more or less as follows:
The 1.00-point fall deduction was in place as of the 2004-05 season, i.e., the first year that IJS was used officially. I think it had not been around for the fall 2003 test events (Nebelhorn and Grand Prix).
Because of complaints, including from fans at Golden Skate some of whom suggested similar changes, a few years ago the fall rules for senior singles events were changed such that the first two falls in a program earn -1.00 each, the third and fourth fall each earn deductions of -2.00 each, and for more falls than that the later ones would earn -3.00 each. So a program with 5 falls gets -9.00 in fall deductions.
A few years after that, maximum PCS ceilings were introduced for programs with falls. Currently,
Serious errors are falls and/or mistakes which result in a break in the delivery of the program. This break can be minimal or more pronounced and noticeable. These errors must be reflected in the mark awarded for each program component. The consequence depends on the severity and impact they have on the fluidity and continuity of the program.
and
*When there is only one error and this error minimally impacts the program, the maximum score of 9.50 is possible as noted above. Note: For the above to apply, the program as a whole is still deemed to be “Excellent”.
**When there are 2 or more errors and these errors only minimally impact the program, the maximum score of 8.75 is possible.
With the +3/-3 GOE system, there were originally mandatory final GOEs for certain errors including falls, which needed to be -3. Later the mandatory final GOEs were relaxed, to encourage judges to award positive aspects first and then reduce for errors. So elements that have several positive characteristics before a fall can earn scores higher than -3 in the old system, -5 in the current scoring, although the final score would still be negative.
E.g., in the current rules a jump or especially a jump combination can earn -3 or -4 if there were enough positive aspects for judges to start from +1 or +2 before subtracting the -5 for a fall.
(There is currently only one mandatory -GOE, in the short program only: mandatory -5 for a jump combination in which only one jump meets the requirements and the other does not, or does not exist.)
The change from +3/-3 to +5/-5 standardized the percentage value of the positive and negative GOEs relative to the base value of the elements, so now an element with -5 GOE will earn exactly half of the base value (which in the case of jumps might be reduced by rotation and/or edge calls). Any fall deductions would be in addition to that GOE penalty.
None of these penalties on their own cancel out the value of successfully rotating a triple or quad jump. But the possibility of penalizing falls in GOE
and in PCS
and in fall deductions means that there is flexibility to build up significant penalties for really disruptive falls -- and especially for really disrupted programs with multiple falls -- with much lesser penalties for otherwise excellent performances than contain one quick fall with quick recovery, and intermediate penalties for a range of disruptiveness in between.