Transfer abroad/Divorce
In theory you could possibly transfer the Irish fund into an equivalent arrangement abroad. In reality whilst this is very possible in terms of a transfer to the UK, a transfer elsewhere is much more problematic (need to seek Revenue approval).
In relation to your second point (separation/divorce), if you go for a divorce one of the elements of the settlement could be a Pensions Adjustment Order, whereby your wife seeks a share of the pension you earned during the period of your marriage. That share would be decided by the Courts (unless you both agreed a settlement between you) based on the case presented. Otherwise as things stand (no divorce) your wife might be entitled to any widows element from your pension on your death (as marriage legally continues to exist).
If you continue with a Judicial Separation, your wife could continue to have an interest in your pension fund (if only to the extent of any death benefits).
If you go for a Divorce, your wife's share of your pension fund (if any) depends on what provision is made for her and the children. If your wife wants a share, she would have to seek a Pensions Adjustment Order as part of the Divorce. What share is granted by the Courts would depend on the overall structure of the financial arrangements.
This is a complicated area needing specialist advice.