Will there be a bicameral Parliament with an Upper House?
What happens to Scottish peers? Will they still have their titles, and will they remain in the British House of Lords?
What happened to Irish peers when Ireland gained its independence?
Not all Irish peers sat in the House of Lords; they elected a subset of their number to do so in 1800 & held by-elections whenever 1 died. Those by-elections stopped after the Irish Free State was founded, but peers already sitting in the Lords stayed their. IIRC the last ones didn’t die off until the '60s or '70s. As to the rest of your question; No, none of that has been settled yet. A bicameral Parliament seems unlikely though; even the original Parliament of Scotland was unicameral.
Yes, the framework for a Scottish goverment has been revealed.
First, the (current) Scottish government published a white paperoutlining in some detail their proposals in this regard. That white paper proposes independence initially on the basis of an interim constitution, with the early convening of a constitutional convention to draw up a permanent constitution for Scotland.
More recently they have published a draft of the Billwhich they propose the (existing) Scottish Parliament would pass to assert Scottish independence and to adopt the interim constitution. The proposed interim constitution is set out in the Bill.
Under the interim constitution, the existing Scottish Parliament, which is unicameral, will continue to function. Whether the permanent constitution will provide for a bicameral legislature will be a matter for the constitutional convention.
The white paper says nothing about the Scottish peerage. At least initially, independent Scotland will be a monarchy under the current British Queen, and there is no reason in that context why the Scottish peerage should not continue. Scottish peers have no role in the current Scottish Parliament or government and there is no proposal to give them any role. Whether Scottish peers will continue to be eligible to be elected to the House of Lords, or to vote in peerage elections, is a matter for the UK government, which so far as I know has said nothing about it.
Prior to 1922, the Irish peers elected 28 of their number to sit in the House of Lords. Each was elected for life, with a fresh election being held every time one died. After 1922 elections ceased to be held, because the office which used to hold them - the Lord Chancellor of Ireland - had ceased to exist. The existing elected peers continued to sit for their lives. The last of them died in 1961.