The Birthday Suit comes with a new set of dialogue. I haven't noticed any extras with the other outfits.
The suggestion to save for the outfits is probably from the general F2P strategy of "save premium currency for things that can't be obtained through normal gameplay." In this game, everything is achievable with time (in theory) except for the outfits.
If you intend to spend diamonds to accelerate the pace of the game, I suggest getting speed boosts. As Tenhou said, in the long run (or with speed boosts) you don't really need extra time blocks. Also consider that a speed boost will help you to unlock achievements faster and thus gain time blocks that way.
The speed boosts are multiplied. So getting two x64 and one x2 will reach the x8192 cap.
As of V.0.77 these are the skills required above level 50:
Level Skill 52 Funny 53 Badass 54 Wisdom 57 Lucky 60 Buff
Thanks for the visual. I'm around 90 time blocks as well, so that seems reasonable for end-game levels. To put some context to that:
- Running all jobs at max level requires 81 time blocks.
- Running the top 9 efficient jobs at max level requires 53 time blocks.
- The bottom 5 jobs have very little impact. See this post.
- Running all hobbies requires 36 time blocks.
- Unless you're going for the hobby achievements, you don't need to level hobbies above 50 with the exception of the 5 listed above.