Just to confirm using the trainer still allows the steam achievements?
Yes Yes Yes Yes Yes
Modding SPECIAL stats via console doesn't allow me to take related perks because it treats it as a clothing bonus. Is there anyway we can get 1 perk point at a time as cheat (so I can pump SPECIAL with perks) or some other SPECIAL increase method?
Assuming you used the "modav" method to adjust your SPECIAL, use the "setav" command instead.
Example: player.setav luck 10
This will set your luck to 10 and allow for the purchase of any perks that require luck 10 or below.
This also doesn't affect boosts given by items. So say you find a hat or something that gives +1 luck...you will now have 11 luck. Alternatively, you can set a SPECIAL to max then use the "modav" command to boost it further as though you were wearing an item that did so.
Hope this helped.