my fix for issue 1.
remove the bulkhead that's in the tank, then to go a local glass shop and buy a peice a glass (that's shapped like a square, and ask them to round the edges, so you don't cut yourself when handling, some places do it for free, other charge for it) that will overlap the hole by about 1inch in all directions, lastly get some aquarium sealer and apply it over the square peice of glass, then afix it over the hole, i have always applied this treatment on the outside of the tank. let the sealent cure (usually within 24hrs) then water test it, and reapply as needed.
i have had the exact same problem with a 55, during tank cleaning i bumped the support bar with my elbow and it snapped. i called up my LFS
and they told me it was replacable, but would need to be special ordered. it ended up costing me about 17bucks with shipping. my LFS
carries All glass aquarium stuff exclusively, if you know of an LFS
that does carry all glass stuff, i would ask them first [based on personal experience]. after you have it in hand, it's just a matter of carefully removing the old one, then filling the new one with sealent, position it in place, wiping off the excess and letting it cure.
if you need more specfics, just ask!