Welcome to the forums and your new XDm.... You'll absolutely love it.
If you are worried about any parts I highly suggest the "upgraded" striker pins provided by PRP. (LINK HERE)
They are a little more heavy duty and are less likely to break from dry firing. I put one in mine and just kept the original for an extra spare.
I've got about 1500 rds through mine now, and it's flawless.
As for Lube I have used many kinds such as:
Smith and Wesson Adv Gun Oil with Cerflon
Mobil One (synthetic)
Royal Purple (synthetic)
and last but not least that I have absolutely fell in love with..... FROG LUBE
as silly as it may sound, it is totally phenomenal. There is nothing like throwing lead down range and seeing the slide and barrel oil itself as your shooting. I prefer the paste over the liquid.
After Four thorough, treatments with (hair dryer for heat) clean up after 200 rds at the range is an absolute breeze. That made me a true believer. I also have used patches after other products show clean and Frog Lube will still pull even more powder out. I just can't say enough about it. (oh, and I am not sponsored, paid or work for them and have no advantage in you using the product)
Anyway - with the XDm less is better - especially keep oil out of the striker channel towards the rear of the slide. As stated earlier, you do not want build up on the striker, that can cause light strikes.
I like to use some Super Lube "synthetic"grease (very very light) on the rails, and it stays put. If you keep your gun clean, you'll have no issues. If you are however in a very dirty environment, then you want to not use grease or keep your gun "wet". Also as stated before dust and sand will stick to your firearm, and the grit will wear down components and probably require premature degradation to them. I keep mine wet, and in my GunVault on my night stand ready to roll.
Hmmm... I can't think of anything else really to share. As far as lube goes, allot of it is personal preference, and you really can't go wrong with any. So what works for some may not work for others, I've tried so much and I am always looking for something to over throw Frog Lube, but I just haven't found it yet. It's that good. IMHO (in my honest opinion)
Enjoy that Beast!
Oh and if you want to see how I apply it, it is very similar to this...