Can a protective order prohibit the plaintiffs' lawyers from laying eyes on some documents/evidence?
Yes, if it is so allowed and ordered by Judge Sweeney.
Will only the judge be able to see the evidence or is it possible that such evidence be ordered protected and kept secret from the judge and the lawyers and therefore kept out of the trial completely?
1. In some cases, only the judge may see certain protective documented evidence. 2. The documented evidence cannot be kept from both the judge and lawyers or out of the trial in a protective order unless there is some compelling constitutional, lawful precedent or need for procedural protection of one or more parties (see page 105 in Case Law on Entering.... and Rule 26 in the others below).