1) Firstly, you _must_ improve your technology of

1) Firstly, you _must_ improve your technology of reworking BGA chips (soldering/desoldering). Because it isn't common problem of desktop motherboards.
2) Lets look at ICH5 DS. Yo can find there that R20 is 'VRMPWRGD' signal. It is not good idea let this signal be not connected.
3) One can restore footers on motherboard. It is difficult. In fact, now I'm only learning to do it. Idea is that: you look what wires were connected with missing footer and with lead-free solder & thin wire (like 'жила МГТФ') make new footer.