lol
1. the double spend issue is still a problem RBF, CPFP, CSV and others still make it possible to bait someone with one tx, but have it not confirm due to another tx confirming that goes to another destination.

2. even the glossy roadmap explains the problem and hints to the solution. 'this caused accounting issues by services that only verify by TXID'
merchants should fully check the tx and wait for a confirm.

3. block inflate.. oooh so ur against blocks being above 0.1mb in 2009, 0.3mb in 2012 0.5mb in 2013 0.7mb in 2014. 0.9mb in 2015..
do you even grasp code/logic/understanding of how bitcoin works, it seems not. or are you just spitting out the same script as blockstream fanatics, like some christmas carol singers

3. as for LN
did you know it requires dual signatures..
meaning the tx is only valid if both sides sign the same thing. meaning a malicious party cannot then create a second malleated tx because the second party would be needed. and that second party wont sign something with obvious changes. thus it wont even be accepted into pools with only one signature.
the truth is LN solves malleability, not the other way round. by dual signing only one correct tx is acceptable thus malleability is not even a process that could be used within LN even if it wasnt fixed