I'm not sure why you would need 4 strut mounts unless it could be shown to you that a) the front strut mount bearings are rusted or binding, rubber cracked or torn away, and b) the rear strut mounts are deteriorated, rusted, rubber torn away, etc.
The estimate seems high to me, even with the 4 new strut mounts and 4 new struts and wheel alignment.
Your other repair sounded too high as well. If you bent even an inner tie rod (more expensive than the tie rod ends) I couldn't see more than $225 or so for this job. You don't need a wheel alignment with a tie rod replacement, only a toe-in adjustment, which is pretty darn easy to do.
I'd suggest you stay out of chain stores and have a competent independent Japanese auto repair shop inspect the car and SHOW YOU the bad strut mounts. While they always tell you to replace the strut mounts with the struts, it makes sense to see what kind of condition they are in. Replacing them adds considerable expense to this job.
As for the struts, yeah, they can be pretty weak at 70K.