How to wear knit lace sweaters?

I got two while knit lace sweaters (more open and delicate
than pointelle) as gifts recently, plus a little black knit lace
shawl that ties in front. One knit lace sweater is similar in
proportion and style to this, with flares at the sleeves:
http://www.newprospects.com/oscommerce/product_info.php?products_id=1050
.... and the other is a button down cardigan, very soft and
fuzzy. These are both so pretty to look at.
I haven't seen anything like these around, but I'm told they
are very popular. Usually when I see clothing so delicate I
think everything else needs to be dressed up to go with it,
but I'm told (by a relative) I can wear them with jeans, for a
sort of dressy casual look, and I could maybe even get away
with wearing them to the office, which is generally a somewhat
conservative business–casual engineer's style office. There
are a few women who dress in fashion–forward clothes that
make it look like they don't care to get promoted (*), and I
don't want to associate myself with that look.
(*) – High heel leather boots with "look at me" jeans, or low–
rise jeans with a line of skin showing below their tight tops,
etc. ... upscale and in good condition but out of line for this
office.
Questions:
1) What would you wear with those sweaters?
2) To what occasions would you wear those outfits?
3) Would the looks be age–inappropriate for a 34 y/o?
4) Should I avoid front ties like that first one, since it adds a
point of bulk right in front of my "yes I'm a mom" belly, which
I try to de–emphasize? I also carry more weight above my
hips than below, and have a thick middle, so I try to select
clothes that create shape there for me.
5) Should I avoid the button–front cardigan for similar reasons?
When unbuttoned, it hangs open in a shapeless boxy way, but
when buttoned the button line tends to tug a bit and get wavy,
if you know what I mean, but not enough to warrant a larger size.
6) Do you find such sweaters snag easily or are hard to maintain?
For the little black shawl, how would it look over a lavender
chiffon dress? I think of the lavendar dress as a summer dress
and black as a winter color. I could wear that combination to a
wedding in April. Perhaps I should save the shawl for wearing with
a LBD, but I'm afraid that by next year (when I'd have the next
occasion to buy a cocktail dress) it would be out of style.
Thanks,
JP
(posting with a bad email address)