There are a few mechanics that can be tightened up or removed to make the game play smoother and make it more welcoming to new players:
Consolidate honor and dishonor into an influence mechanic Remove Imperial Favor Consolidate into a single deck, this was probably the biggest barrier of entry I found when teaching new players. Remove rulebook adjustments to personality costs, the value on the card is what is paid. Restrict in the deck building rules. Remove honor gain on recruitment and balance the game accordingly. Keywords... so many keywords. If it's a mechanic include it in the personality's ability text. How is a new player supposed to remember that "Mantis" and "Naval" mean two different things mechanically? Consolidate all movement based mechanics into a "Mobile" mechanic combining Cavalry, Naval, etc. Dueling is a major part of L5R, but it could be simplified, plus it doesn't necessarily take into account Shugenja duels. Have duel mechanics printed on the specific duel card that is played.