  Given a graph $G$, two edges $e_{1},e_{2}\in E(G)$ are said to have a common
edge $e$ if $e$ joins an endvertex of $e_{1}$ to an endvertex of $e_{2}$. A
subset $B\subseteq E(G)$ is an edge open packing set in $G$ if no two edges of
$B$ have a common edge in $G$, and the maximum cardinality of such a set in $G$
is called the edge open packing number, $\rho_{e}^{o}(G)$, of $G$. In this
paper, we prove that the decision version of the edge open packing number is
NP-complete even when restricted to graphs with universal vertices, Eulerian
bipartite graphs, and planar graphs with maximum degree $4$, respectively. In
contrast, we present a linear-time algorithm that computes the edge open
packing number of a tree. We also resolve two problems posed in the seminal
paper [Edge open packing sets in graphs, RAIRO-Oper.\ Res.\ 56 (2022)
3765--3776]. Notably, we characterize the graphs $G$ that attain the upper
bound $\rho_e^o(G)\le |E(G)|/\delta(G)$, and provide lower and upper bounds for
the edge-deleted subgraph of a graph and establish the corresponding
realization result.
