I think some people are too concerned with who the private investors and why some shares were sold off the exchange - there's entirely valid reasons for the latter.  But there ARE legitimate questions that should be addressed, especially if the deal is going to be somehow changed mid-flight.

1.  Are all funds raised from IPO going to the company and being used to the benefit of investors?  i.e. if there's surplus after purchasing the hardware etc does that extra get used to expand the hashing power or disappear into someone's back pocket?

2.  Whilst the number of shares and timing of each batch can be changed there's no entitlement to change the TOTAL shares that will be sold to the public (or the private shares would end up not just owning a disproportionate amount of initial hashing power - but also of reinvested capital).  Can reassurance be given that:
a) All shares stated to be sold to the public WILL be sold - even if the exact dates/batches on which they're sold changes.
b) No shares will be sold at below the initial price for the shares already sold.

3.  Can reassurance be given that no management fees, consultancy fees or similar will be paid to the managers, private investors or their friends/family to dilute earnings.

4.  Some of the documentation reads as though a new data centre is being constructed for this project.  If this is the case can assurances be provided that any other income from a data-centre/infrastructure funded by investors in this IPO will also be treated as revenue to be distributed after costs to investors.  We wouldn't want other people's mining gear free-loading off investors there without benefit to investors.

5.  Whilst transparency of costs has been promised, no comment has been made about transparency of handling of IPO funds.  Is it the intention to provide accounts properly documenting the use of funds raised in IPO and from private investors?

6.  Is the initial hashing power per share a minimum, an estimate or a maximum?  i.e. what happens if actual hashing pwoer received varies due to circumstances beyond the issuer's control?

7.  What guarantees have been provided by the hardware supplier in terms of delivery date?  We may not know exactly WHAT the date is, but there's a date after which a refund would be preferable to delivery (as the hardware would never pay for itself from mining).  At what date is a full refund of all funds paid to them allowed to be requested?  Have they provided sufficient financial disclosure that issuer is confident such a refund could and would be honoured in the event they were unable to deliver the hardware by such a deadline?  Estimates of delivery are fine for planning purposes - but a hard deadline beyond which they are in default and must refund (and/or pay penalties) is essential when signing a contract.

I didn't bother asking questions whilst this was only on Bitfunder - as contracts can be edited by issuers there at will.  But now it's showing for approval on BTC-TC some due diligence is appropriate as contracts there are intended to be final and certainly can't just be arbitrarily changed by an issuer.