I don't think it's "stupid" to change stuff just because you want to try something different. It's a hobby and it's your money. New 105 groups are cheap from UK and if you get the 32t cassette you may end up with an easier gear. The rear wheel could be a problem but I think you can mount 10 cogs of the 11 speed cassette to the older 8/9/10 freehubs. There are other work-arounds if you search.