@Halsebee
In response to your first question: It depends on how you count platforms. Are we counting platform numbers, or, just physical platforms? Clapham North Station has the famously small "island" platform which you could argue is one (1) physical platform but has two (2) logical platform numbers. Remember to bear in mind many platforms (both physical and logical) are shared between lines and are not representative of the total number of platforms on the system.
Trying to give a result with the above complications makes presentation of the data quite difficult, so I will try to keep it simple and include logical platforms. For example: Clapham North Station has a single island platform but it has platform numbers 1 and 2; therefore, I count this as two (2) platforms on the Northern line.
Bakerloo Line
1 station has 3 platforms (total of 3 platforms)
24 stations have 2 platforms (total of 48 platforms)
Total of 25 stations and 51 platforms averaging 2.04 platforms per station.
Central Line
43 stations have 2 platforms (total of 86 platforms)
4 stations have 3 platforms (total of 12 platforms)
2 stations have 4 platforms (total of 8 platforms)
Total of 49 stations and 106 platforms averaging 2.163 platforms per station.
Circle Line
32 stations have 2 platform (total of 64 platforms)
2 stations have 3 platforms (total of 6 platforms)
2 stations have 4 platforms (total of 8 platforms)
Total of 36 stations and 78 platforms averaging 2.167 platforms per station.
District Line
1 station has 1 platform (total of 1 platform)
46 stations have 2 platforms (total of 92 platforms)
7 stations have 3 platforms (total of 21 platforms)
6 stations have 4 platforms (total of 24 platforms)
Total of 60 stations and 138 platforms averaging 2.3 platforms per station.
Hammersmith & City Line
24 stations have 2 platforms (total of 48 platforms)
2 stations have 3 platforms (total of 6 platforms)
3 stations have 4 platforms (total of 12 platforms)
Total of 29 stations and 66 platforms averaging 2.276 platforms per station.
Jubilee Line
24 stations have 2 platforms (total of 48 platforms)
3 stations have 3 platforms (total of 9 platforms)
Total of 27 stations and 57 platforms averaging 2.375 platforms per station.
Metropolitan Line
1 station has 1 platform (total of 1 platform)
23 stations have 2 platforms (total of 46 platforms)
3 stations have 3 platforms (total of 9 platforms)
6 stations have 4 platforms (total of 24 platforms)
1 station has 6 platforms (total of 6 platforms)
Total of 34 stations and 86 platforms averaging 2.529 platforms per station.
Northern Line
1 station has 1 platform (total of 1 platform)
42 stations have 2 platforms (total of 84 platforms)
3 stations have 3 platforms (total of 9 platforms)
4 stations have 4 platforms (total of 16 platforms)
2 stations have 5 platforms (total of 10 platforms)
Total of 52 stations and 120 platforms averaging 2.3 platforms per station.
Piccadilly Line
1 station has 1 platform (total of 1 platform)
46 stations have 2 platforms (total of 92 platforms)
5 stations have 4 platforms (total of 20 platforms)
Total of 53 stations and 113 platforms averaging 2.13 platforms per station.
Victoria Line
15 stations have 2 platforms (total of 30 platforms)
1 station has 3 platforms (total of 3 platforms)
Total of 16 stations and 33 platforms averaging 2.0625 platforms per station.
Waterloo & City Line
2 stations have 2 platforms (total of 4 platforms)
Total of 2 stations and 4 platforms averaging 2 platforms per station.
If anyone spots any mistakes, let me know.