Can I use an impact to remove everything?

Hey everyone

New to the power tool game. Been using a ratcheting breaker bar with for last 10 years of wrenching. Recently purchased a Milwaukee M12 Right Angle Impact. 

Questions for the shop gurus

1. Can I use it to remove all nuts/bolts/fasteners (NOT Spark plugs ofcourse)
2. It has an auto tighten mode that stops at 15 ft-lbs. Safe to thread by hand then use this?
3. Avoid on rust I assume otherwise it will snap bolts?

Thanks! 

1. Can I use it to remove all nuts/bolts/fasteners (NOT Spark plugs of course)
   1. Pretty much. Be cautious on smaller bolts, but for the most part you can impact most bolts. You are correct, never use an impact on spark plugs. 
2. It has an auto tighten mode that stops at 15 ft-lbs. Safe to thread by hand then use this?
   1. Go for it. I do prefer to start mine by hand to ensure nothing cross-threads, but yes from there send it home. 15ft-lbs, naturally you'll have to tighten to spec afterwards. Depending on the criticality of the bolt I will use full power impact to set it. 
3. Avoid on rust I assume otherwise it will snap bolts?
   1. 50/50. I wouldn't avoid it, the hammering of the impact itself can definitely help break things loose, you will snap bolts at times, but those are probably bolts you wouldn't want to re-use anyway. Send it!

I have snapped more rusty bolts with a breaker bar than with my impact.  I have theorized that the hammering will help prevent the bolt from breaking by knocking things loose while just applying eleventy-billion foot pounds of torque with a breaker bar just lets the rust knuckle down and then the force breaks the steel.  If the impact won't budge it, I go for the torch if I can.

Awesome. Thanks for the feedback fellas. Picking up my torque wrench from the calibration shop today and I'll be off to the races!

I use my Milwaukee 3/8 stubby impact on everything. Especially the rusty stuff. 

In reply to Toyman! :

I use my dewalt 1/2" impact and impact driver for as much as I can. I've been contemplating getting hte 3/8" ratchet. I loved using my air ratchet, just hated the hose in the damn way literally all the time.

I wouldn't suggest using it to remove your pants, but i aintcher mammy. 

I had a big DeWalt electric impact wrench which was great but heavy. 

I recently picked up a pneumatic impact wrench for cheap at a garage sale.  Now its my go-to bolt weapon.  

Side note: My brother is a technician at a dealership.  He says lots of the mechanics use impact ratchet wrenches on spark plugs. 

How do you all feel about impact swivel sockets?

https://www.canadiantire.ca/en/pdp/maximum-1-2-in-drive-swivel-impact-socket-set-7-pc-metric-crmo-0580319p.0580319.html?rq=impact+swivel+socket#srp

Ok I use mine for loosening everything and tightening almost everything. Sorry/not sorry. 

I actually prefer to use my 3/8" impact to remove old spark plugs from aluminum heads.  I just give it quick, short trigger pulls. I think that you're far less likely to pull out the threads along with the plug with the hammering of the impact than with a breaker bar, especially if the plugs have been in there for more than 50k miles.