you pointed out that straight from tut island to skilling was an issue. i created 8 accounts 6 on one ip and 2 others with second ip. all botted tut island 6 of them survived 2 which got banned where insanely botted 606060 in 2 days the other one made it to 50 wc from just normal logs. i was testing the limits etc.
my beliefs of your questions.
1. could be banned due to same ip then chainbanned WC has huge banrate.
2. the script you where using was a free script with many users and jagex established a behavior/pattern.
3. try to remake this scenario with Mirror mode seperate ip on both accounts and use a premium script. you SHOULD see better results.
EDIT: all the accounts where fresh created and botted same day.