diff --git a/cmd/analyze/scanner.go b/cmd/analyze/scanner.go
index ae5ab3f..2f0f797 100644
--- a/cmd/analyze/scanner.go
+++ b/cmd/analyze/scanner.go
@@ -471,11 +471,13 @@ func calculateDirSizeConcurrent(root string, largeFileChan chan<- fileEntry, duS
 						defer func() { <-duSem }()
 						return getDirectorySizeFromDu(path)
 					}()
-					if err == nil && size > 0 {
-						atomic.AddInt64(&total, size)
+					if err != nil || size <= 0 {
+						size = calculateDirSizeFast(path, filesScanned, dirsScanned, bytesScanned, currentPath)
+					} else {
 						atomic.AddInt64(bytesScanned, size)
-						atomic.AddInt64(dirsScanned, 1)
 					}
+					atomic.AddInt64(&total, size)
+					atomic.AddInt64(dirsScanned, 1)
 				}(fullPath)
 				continue
 			}
diff --git a/install.sh b/install.sh
index 8a45c84..b7d05be 100755
--- a/install.sh
+++ b/install.sh
@@ -52,6 +52,39 @@ log_error() { echo -e "${YELLOW}${ICON_ERROR}${NC} $1"; }
 log_admin() { [[ ${VERBOSE} -eq 1 ]] && echo -e "${BLUE}${ICON_ADMIN}${NC} $1"; }
 log_confirm() { [[ ${VERBOSE} -eq 1 ]] && echo -e "${BLUE}${ICON_CONFIRM}${NC} $1"; }
 
+safe_rm() {
+    local target="${1:-}"
+    local tmp_root
+
+    if [[ -z "$target" ]]; then
+        log_error "safe_rm: empty path"
+        return 1
+    fi
+    if [[ ! -e "$target" ]]; then
+        return 0
+    fi
+
+    tmp_root="${TMPDIR:-/tmp}"
+    case "$target" in
+        "$tmp_root" | /tmp)
+            log_error "safe_rm: refusing to remove temp root: $target"
+            return 1
+            ;;
+        "$tmp_root"/* | /tmp/*) ;;
+        *)
+            log_error "safe_rm: refusing to remove non-temp path: $target"
+            return 1
+            ;;
+    esac
+
+    if [[ -d "$target" ]]; then
+        find "$target" -depth \( -type f -o -type l \) -exec rm -f {} + 2> /dev/null || true
+        find "$target" -depth -type d -exec rmdir {} + 2> /dev/null || true
+    else
+        rm -f "$target" 2> /dev/null || true
+    fi
+}
+
 # Install defaults
 INSTALL_DIR="/usr/local/bin"
 CONFIG_DIR="$HOME/.config/mole"
@@ -100,7 +133,16 @@ resolve_source_dir() {
 
     local tmp
     tmp="$(mktemp -d)"
-    trap "stop_line_spinner 2>/dev/null; rm -rf \"$tmp\"" EXIT
+
+    # Safe cleanup function for temporary directory
+    cleanup_tmp() {
+        stop_line_spinner 2> /dev/null || true
+        if [[ -z "${tmp:-}" ]]; then
+            return 0
+        fi
+        safe_rm "$tmp"
+    }
+    trap cleanup_tmp EXIT
 
     local branch="${MOLE_VERSION:-}"
     if [[ -z "$branch" ]]; then
diff --git a/lib/core/base.sh b/lib/core/base.sh
index 95b3ae4..ce131ca 100644
--- a/lib/core/base.sh
+++ b/lib/core/base.sh
@@ -539,9 +539,14 @@ register_temp_dir() {
 mktemp_file() {
     local prefix="${1:-mole}"
     local temp
+    local error_msg
     # Use TMPDIR if set, otherwise /tmp
     # Add .XXXXXX suffix to work with both BSD and GNU mktemp
-    temp=$(mktemp "${TMPDIR:-/tmp}/${prefix}.XXXXXX") || return 1
+    if ! error_msg=$(mktemp "${TMPDIR:-/tmp}/${prefix}.XXXXXX" 2>&1); then
+        echo "Error: Failed to create temporary file: $error_msg" >&2
+        return 1
+    fi
+    temp="$error_msg"
     register_temp_file "$temp"
     echo "$temp"
 }
diff --git a/lib/core/common.sh b/lib/core/common.sh
index 923122a..2408294 100755
--- a/lib/core/common.sh
+++ b/lib/core/common.sh
@@ -34,7 +34,7 @@ update_via_homebrew() {
     temp_upgrade=$(mktemp_file "brew_upgrade")
 
     # Set up trap for interruption (Ctrl+C) with inline cleanup
-    trap "stop_inline_spinner 2>/dev/null; rm -f \"$temp_update\" \"$temp_upgrade\" 2>/dev/null; echo \"\"; exit 130" INT TERM
+    trap 'stop_inline_spinner 2>/dev/null; safe_remove "$temp_update" true; safe_remove "$temp_upgrade" true; echo ""; exit 130' INT TERM
 
     # Update Homebrew
     if [[ -t 1 ]]; then
@@ -73,7 +73,8 @@ update_via_homebrew() {
     trap - INT TERM
 
     # Cleanup temp files
-    rm -f "$temp_update" "$temp_upgrade"
+    safe_remove "$temp_update" true
+    safe_remove "$temp_upgrade" true
 
     if echo "$upgrade_output" | grep -q "already installed"; then
         local installed_version